In this HackerRank White Falcon And Tree problem solution, you are given a tree with N nodes. and each node contains a linear function. and first, we need to assign the ax + b function of all the nodes on the path and then calculate the modulo of the function with the given expression.
Problem solution in Java Programming.
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;
public class Solution {
static InputStream is;
static PrintWriter out;
static String INPUT = "";
static int mod = 1000000007;
static void solve()
{
int n = ni();
int[][] co = new int[n][];
for(int i = 0;i < n;i++){
co[i] = new int[]{ni(), ni()};
}
int[] from = new int[n-1];
int[] to = new int[n-1];
for(int i = 0;i < n-1;i++){
from[i] = ni()-1;
to[i] = ni()-1;
}
int[][] g = packU(n, from, to);
int[][] pars = parents3(g, 0);
int[] par = pars[0], ord = pars[1], dep = pars[2];
int[] clus = decomposeToHeavyLight(g, par, ord);
int[][] cluspath = clusPaths(clus, ord);
int[] clusiind = clusIInd(cluspath, n);
SegmentTreeNodePlus[] sts = new SegmentTreeNodePlus[cluspath.length];
for(int i = 0;i < cluspath.length;i++){
int[][] lco = new int[cluspath[i].length][];
for(int j = 0;j < cluspath[i].length;j++){
lco[j] = co[cluspath[i][j]];
}
sts[i] = new SegmentTreeNodePlus(lco);
}
int[][] spar = logstepParents(par);
int Q = ni();
for(int z = 0;z < Q;z++){
int t = ni();
if(t == 1){
int u = ni()-1, v = ni()-1, a = ni(), b = ni();
int lca = lca2(u, v, spar, dep);
int[][] pr = query2(u, lca, v, clus, cluspath, clusiind, par);
for(int[] e : pr){
sts[e[0]].update(Math.min(e[1], e[2]), Math.max(e[1], e[2])+1, a, b);
}
}else{
int u = ni()-1, v = ni()-1;
long x = ni();
int lca = lca2(u, v, spar, dep);
int[][] pr = query2(u, lca, v, clus, cluspath, clusiind, par);
for(int[] e : pr){
if(e[1] <= e[2]){
x = sts[e[0]].apply(e[1], e[2]+1, x, false);
}else{
x = sts[e[0]].apply(e[2], e[1]+1, x, true);
}
}
out.println(x);
}
}
}
public static int lca2(int a, int b, int[][] spar, int[] depth) {
if (depth[a] < depth[b]) {
b = ancestor(b, depth[b] - depth[a], spar);
} else if (depth[a] > depth[b]) {
a = ancestor(a, depth[a] - depth[b], spar);
}
if (a == b)
return a;
int sa = a, sb = b;
for (int low = 0, high = depth[a], t = Integer.highestOneBit(high), k = Integer
.numberOfTrailingZeros(t); t > 0; t >>>= 1, k--) {
if ((low ^ high) >= t) {
if (spar[k][sa] != spar[k][sb]) {
low |= t;
sa = spar[k][sa];
sb = spar[k][sb];
} else {
high = low | t - 1;
}
}
}
return spar[0][sa];
}
protected static int ancestor(int a, int m, int[][] spar) {
for (int i = 0; m > 0 && a != -1; m >>>= 1, i++) {
if ((m & 1) == 1)
a = spar[i][a];
}
return a;
}
public static int[][] logstepParents(int[] par) {
int n = par.length;
int m = Integer.numberOfTrailingZeros(Integer.highestOneBit(n - 1)) + 1;
int[][] pars = new int[m][n];
pars[0] = par;
for (int j = 1; j < m; j++) {
for (int i = 0; i < n; i++) {
pars[j][i] = pars[j - 1][i] == -1 ? -1
: pars[j - 1][pars[j - 1][i]];
}
}
return pars;
}
public static class SegmentTreeNodePlus {
public int M, H, N;
public Node[] node;
public int[][] cover;
private static class Node
{
long co;
long lc;
long rc;
public Node() {
co = 1;
lc = rc = 0;
}
public Node(long co, long lc, long rc) {
this.co = co;
this.lc = lc;
this.rc = rc;
}
public long apply(long x, boolean dir)
{
if(!dir){
return (co * x + lc) % mod;
}else{
return (co * x + rc) % mod;
}
}
}
public SegmentTreeNodePlus(int[][] co)
{
N = co.length;
M = Integer.highestOneBit(Math.max(N-1, 1))<<2;
H = M>>>1;
node = new Node[M];
cover = new int[H][];
for(int i = 0;i < N;i++){
node[H+i] = new Node(co[i][0], co[i][1], co[i][1]);
}
for(int i = H-1;i >= 1;i--)propagate(i);
}
private void propagate(int cur)
{
node[cur] = prop2(node[2*cur], node[2*cur+1], cover[cur], node[cur], H/Integer.highestOneBit(cur));
}
static final int mod = 1000000007;
private Node prop2(Node L, Node R, int[] cover, Node C, int len)
{
if(L != null && R != null){
if(C == null)C = new Node();
if(cover == null){
C.co = L.co * R.co % mod;
C.lc = (R.co * L.lc + R.lc) % mod;
C.rc = (L.co * R.rc + L.rc) % mod;
}else{
long co = cover[0], c = cover[1];
for(int x = len;x > 1;x >>>= 1){
long nco = co * co % mod;
long nc = (co * c + c) % mod;
co = nco;
c = nc;
}
C.co = co;
C.lc = C.rc = c;
}
return C;
}else if(L != null){
return prop1(L, cover, C, len);
}else if(R != null){
return prop1(R, cover, C, len);
}else{
return null;
}
}
private Node prop1(Node L, int[] cover, Node C, int len)
{
if(C == null)C = new Node();
if(cover == null){
C.co = L.co;
C.lc = L.lc;
C.rc = L.rc;
}else{
long co = cover[0], c = cover[1];
for(int x = len;x > 1;x >>>= 1){
long nco = co * co % mod;
long nc = (co * c + c) % mod;
co = nco;
c = nc;
}
C.co = co;
C.lc = C.rc = c;
}
return C;
}
int[] temp = null;
public void update(int l, int r, int a, int b) {
temp = new int[]{a, b};
if(l < r)update(l, r, a, b, 0, H, 1); }
protected void update(int l, int r, int a, int b, int cl, int cr, int cur)
{
if(cur >= H){
node[cur].co = a;
node[cur].lc = node[cur].rc = b;
}else if(l <= cl && cr <= r){
cover[cur] = temp;
propagate(cur);
}else{
int mid = cl+cr>>>1;
boolean bp = false;
if(cover[cur] != null){
if(2*cur < H){
cover[2*cur] = cover[cur];
cover[2*cur+1] = cover[cur];
cover[cur] = null;
bp = true;
}else{
node[2*cur].co = cover[cur][0];
node[2*cur].lc = node[2*cur].rc = cover[cur][1];
node[2*cur+1].co = cover[cur][0];
node[2*cur+1].lc = node[2*cur+1].rc = cover[cur][1];
cover[cur] = null;
}
}
if(cl < r && l < mid){
update(l, r, a, b, cl, mid, 2*cur);
}else if(bp){
propagate(2*cur);
}
if(mid < r && l < cr){
update(l, r, a, b, mid, cr, 2*cur+1);
}else if(bp){
propagate(2*cur+1);
}
propagate(cur);
}
}
public long apply(int l, int r, long x, boolean dir) {
return apply(l, r, x, dir, 0, H, 1);
}
protected long apply(int l, int r, long x, boolean dir, int cl, int cr, int cur)
{
if(l <= cl && cr <= r){
return node[cur].apply(x, dir);
}else{
int mid = cl+cr>>>1;
if(cover[cur] != null){
long co = cover[cur][0], c = cover[cur][1];
for(int h = Math.min(r, cr) - Math.max(l, cl);h > 0;h >>>= 1){
if((h&1) == 1){
x = (co * x + c) % mod;
}
long nco = co * co % mod;
long nc = (co * c + c) % mod;
co = nco;
c = nc;
}
return x;
}
if(!dir){
if(cl < r && l < mid){
x = apply(l, r, x, dir, cl, mid, 2*cur);
}
if(mid < r && l < cr){
x = apply(l, r, x, dir, mid, cr, 2*cur+1);
}
}else{
if(mid < r && l < cr){
x = apply(l, r, x, dir, mid, cr, 2*cur+1);
}
if(cl < r && l < mid){
x = apply(l, r, x, dir, cl, mid, 2*cur);
}
}
return x;
}
}
}
public static int[][] parents3(int[][] g, int root) {
int n = g.length;
int[] par = new int[n];
Arrays.fill(par, -1);
int[] depth = new int[n];
depth[0] = 0;
int[] q = new int[n];
q[0] = root;
for (int p = 0, r = 1; p < r; p++) {
int cur = q[p];
for (int nex : g[cur]) {
if (par[cur] != nex) {
q[r++] = nex;
par[nex] = cur;
depth[nex] = depth[cur] + 1;
}
}
}
return new int[][] { par, q, depth };
}
public static int[] decomposeToHeavyLight(int[][] g, int[] par, int[] ord)
{
int n = g.length;
int[] size = new int[n];
Arrays.fill(size, 1);
for(int i = n-1;i > 0;i--)size[par[ord[i]]] += size[ord[i]];
int[] clus = new int[n];
Arrays.fill(clus, -1);
int p = 0;
outer:
for(int i = 0;i < n;i++){
int u = ord[i];
if(clus[u] == -1)clus[u] = p++;
for(int v : g[u]){
if(par[u] != v && size[v] >= size[u]/2){
clus[v] = clus[u];
continue outer;
}
}
for(int v : g[u]){
if(par[u] != v){
clus[v] = clus[u];
break;
}
}
}
return clus;
}
public static int[][] clusPaths(int[] clus, int[] ord)
{
int n = clus.length;
int[] rp = new int[n];
int sup = 0;
for(int i = 0;i < n;i++){
rp[clus[i]]++;
sup = Math.max(sup, clus[i]);
}
sup++;
int[][] row = new int[sup][];
for(int i = 0;i < sup;i++)row[i] = new int[rp[i]];
for(int i = n-1;i >= 0;i--){
row[clus[ord[i]]][--rp[clus[ord[i]]]] = ord[i];
}
return row;
}
public static int[] clusIInd(int[][] clusPath, int n)
{
int[] iind = new int[n];
for(int[] path : clusPath){
for(int i = 0;i < path.length;i++){
iind[path[i]] = i;
}
}
return iind;
}
public static int[][] query2(int x, int anc, int y, int[] clus, int[][] cluspath, int[] clusiind, int[] par)
{
int[][] stack = new int[60][];
int sp = 0;
int cx = clus[x];
int indx = clusiind[x];
while(cx != clus[anc]){
stack[sp++] = new int[]{cx, indx, 0};
int con = par[cluspath[cx][0]];
indx = clusiind[con];
cx = clus[con];
}
stack[sp++] = new int[]{cx, indx, clusiind[anc]};
int top = sp;
int cy = clus[y];
int indy = clusiind[y];
while(cy != clus[anc]){
stack[sp++] = new int[]{cy, 0, indy};
int con = par[cluspath[cy][0]];
indy = clusiind[con];
cy = clus[con];
}
if(clusiind[anc] < indy){
stack[sp++] = new int[]{cy, clusiind[anc]+1, indy};
}
for(int p = top, q = sp-1;p < q;p++,q--){
int[] dum = stack[p]; stack[p] = stack[q]; stack[q] = dum;
}
return Arrays.copyOf(stack, sp);
}
static int[][] packU(int n, int[] from, int[] to) {
int[][] g = new int[n][];
int[] p = new int[n];
for (int f : from)
p[f]++;
for (int t : to)
p[t]++;
for (int i = 0; i < n; i++)
g[i] = new int[p[i]];
for (int i = 0; i < from.length; i++) {
g[from[i]][--p[from[i]]] = to[i];
g[to[i]][--p[to[i]]] = from[i];
}
return g;
}
public static void main(String[] args) throws Exception
{
is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
out = new PrintWriter(System.out);
solve();
out.flush();
}
private static boolean eof()
{
if(lenbuf == -1)return true;
int lptr = ptrbuf;
while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false;
try {
is.mark(1000);
while(true){
int b = is.read();
if(b == -1){
is.reset();
return true;
}else if(!isSpaceChar(b)){
is.reset();
return false;
}
}
} catch (IOException e) {
return true;
}
}
private static byte[] inbuf = new byte[1024];
static int lenbuf = 0, ptrbuf = 0;
private static int readByte()
{
if(lenbuf == -1)throw new InputMismatchException();
if(ptrbuf >= lenbuf){
ptrbuf = 0;
try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
if(lenbuf <= 0)return -1;
}
return inbuf[ptrbuf++];
}
private static boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
private static int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
private static double nd() { return Double.parseDouble(ns()); }
private static char nc() { return (char)skip(); }
private static String ns()
{
int b = skip();
StringBuilder sb = new StringBuilder();
while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
sb.appendCodePoint(b);
b = readByte();
}
return sb.toString();
}
private static char[] ns(int n)
{
char[] buf = new char[n];
int b = skip(), p = 0;
while(p < n && !(isSpaceChar(b))){
buf[p++] = (char)b;
b = readByte();
}
return n == p ? buf : Arrays.copyOf(buf, p);
}
private static char[][] nm(int n, int m)
{
char[][] map = new char[n][];
for(int i = 0;i < n;i++)map[i] = ns(m);
return map;
}
private static int[] na(int n)
{
int[] a = new int[n];
for(int i = 0;i < n;i++)a[i] = ni();
return a;
}
private static int ni()
{
int num = 0, b;
boolean minus = false;
while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
if(b == '-'){
minus = true;
b = readByte();
}
while(true){
if(b >= '0' && b <= '9'){
num = num * 10 + (b - '0');
}else{
return minus ? -num : num;
}
b = readByte();
}
}
private static long nl()
{
long num = 0;
int b;
boolean minus = false;
while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
if(b == '-'){
minus = true;
b = readByte();
}
while(true){
if(b >= '0' && b <= '9'){
num = num * 10 + (b - '0');
}else{
return minus ? -num : num;
}
b = readByte();
}
}
}
Problem solution in C++ programming.
#define _CRT_SECURE_NO_WARNINGS
#include <string>
#include <vector>
#include <algorithm>
#include <numeric>
#include <set>
#include <map>
#include <queue>
#include <iostream>
#include <sstream>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstring>
#include <cctype>
#include <cassert>
#include <limits>
#include <functional>
#define rep(i,n) for(int (i)=0;(i)<(int)(n);++(i))
#define rer(i,l,u) for(int (i)=(int)(l);(i)<=(int)(u);++(i))
#define reu(i,l,u) for(int (i)=(int)(l);(i)<(int)(u);++(i))
#if defined(_MSC_VER) || __cplusplus > 199711L
#define aut(r,v) auto r = (v)
#else
#define aut(r,v) typeof(v) r = (v)
#endif
#define each(it,o) for(aut(it, (o).begin()); it != (o).end(); ++ it)
#define all(o) (o).begin(), (o).end()
#define pb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))
#define mset(m,v) memset(m,v,sizeof(m))
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL
using namespace std;
typedef vector<int> vi; typedef pair<int,int> pii; typedef vector<pair<int,int> > vpii;
typedef long long ll; typedef vector<long long> vl; typedef pair<long long,long long> pll; typedef vector<pair<long long,long long> > vpll;
typedef vector<string> vs; typedef long double ld;
template<typename T, typename U> inline void amin(T &x, U y) { if(y < x) x = y; }
template<typename T, typename U> inline void amax(T &x, U y) { if(x < y) x = y; }
template<int MOD>
struct ModInt {
static const int Mod = MOD;
unsigned x;
ModInt(): x(0) { }
ModInt(signed sig) { int sigt = sig % MOD; if(sigt < 0) sigt += MOD; x = sigt; }
ModInt(signed long long sig) { int sigt = sig % MOD; if(sigt < 0) sigt += MOD; x = sigt; }
int get() const { return (int)x; }
ModInt &operator+=(ModInt that) { if((x += that.x) >= MOD) x -= MOD; return *this; }
ModInt &operator-=(ModInt that) { if((x += MOD - that.x) >= MOD) x -= MOD; return *this; }
ModInt &operator*=(ModInt that) { x = (unsigned long long)x * that.x % MOD; return *this; }
ModInt operator+(ModInt that) const { return ModInt(*this) += that; }
ModInt operator-(ModInt that) const { return ModInt(*this) -= that; }
ModInt operator*(ModInt that) const { return ModInt(*this) *= that; }
};
typedef ModInt<1000000007> mint;
//y = ax + b
struct LinearExpr {
mint a, b;
LinearExpr(): a(1), b(0) { }
LinearExpr(mint a_, mint b_): a(a_), b(b_) { }
LinearExpr(const LinearExpr &val, int) { a = val.a, b = val.b; }
LinearExpr &operator+=(const LinearExpr &that) {
b = b * that.a + that.b;
a = a * that.a;
return *this;
}
LinearExpr operator+(const LinearExpr &that) const {
return LinearExpr(*this) += that;
}
LinearExpr operator*(int k) const {
LinearExpr a = *this, r;
while(k) {
if(k & 1) r += a;
a += a;
k >>= 1;
}
return r;
}
mint evalute(mint x) const { return a * x + b; }
};
typedef LinearExpr Val;
struct Sum {
LinearExpr forward, backward;
Sum(): forward(), backward() { }
Sum(const Val &val, int): forward(val), backward(val) { }
Sum &operator+=(const Sum &that) {
forward += that.forward;
backward = that.backward + backward;
return *this;
}
Sum operator+(const Sum &that) const { return Sum(*this) += that; }
};
struct Laziness {
bool fill;
LinearExpr expr;
Laziness(): fill(false) { }
Laziness(LinearExpr expr_): fill(true), expr(expr_) { }
Laziness &operator+=(const Laziness &that) {
if(that.fill)
*this = that;
return *this;
}
void addToVal(Val &val, int) const {
if(fill)
val = expr;
}
void addToSum(Sum &sum, int left, int right) const {
if(fill) {
LinearExpr multiplicated = expr * (right - left);
sum.forward = sum.backward = multiplicated;
}
}
};
struct SegmentTree {
vector<Val> leafs;
vector<Sum> nodes;
vector<Laziness> laziness;
vector<int> leftpos, rightpos;
int n, n2;
void init(int n_, const Val &v = Val()) { init(vector<Val>(n_, v)); }
void init(const vector<Val> &u) {
n = 1; while(n < (int)u.size()) n *= 2;
n2 = (n - 1) / 2 + 1;
leafs = u; leafs.resize(n, Val());
nodes.resize(n);
for(int i = n-1; i >= n2; -- i)
nodes[i] = Sum(leafs[i*2-n], i*2-n) + Sum(leafs[i*2+1-n], i*2+1-n);
for(int i = n2-1; i > 0; -- i)
nodes[i] = nodes[i*2] + nodes[i*2+1];
laziness.assign(n, Laziness());
leftpos.resize(n); rightpos.resize(n);
for(int i = n-1; i >= n2; -- i) {
leftpos[i] = i*2-n;
rightpos[i] = (i*2+1-n) + 1;
}
for(int i = n2-1; i > 0; -- i) {
leftpos[i] = leftpos[i*2];
rightpos[i] = rightpos[i*2+1];
}
}
Val get(int i) {
int indices[128];
int k = getIndices(indices, i, i+1);
propagateRange(indices, k);
return leafs[i];
}
Sum getRangeCommutative(int i, int j) {
int indices[128];
int k = getIndices(indices, i, j);
propagateRange(indices, k);
Sum res = Sum();
for(int l = i + n, r = j + n; l < r; l >>= 1, r >>= 1) {
if(l & 1) res += sum(l ++);
if(r & 1) res += sum(-- r);
}
return res;
}
Sum getRange(int i, int j) {
int indices[128];
int k = getIndices(indices, i, j);
propagateRange(indices, k);
Sum res = Sum();
for(; i && i + (i&-i) <= j; i += i&-i)
res += sum((n+i) / (i&-i));
for(k = 0; i < j; j -= j&-j)
indices[k ++] = (n+j) / (j&-j) - 1;
while(-- k >= 0) res += sum(indices[k]);
return res;
}
void set(int i, const Val &x) {
int indices[128];
int k = getIndices(indices, i, i+1);
propagateRange(indices, k);
leafs[i] = x;
mergeRange(indices, k);
}
void addToRange(int i, int j, const Laziness &x) {
if(i >= j) return;
int indices[128];
int k = getIndices(indices, i, j);
propagateRange(indices, k);
int l = i + n, r = j + n;
if(l & 1) { int p = (l ++) - n; x.addToVal(leafs[p], p); }
if(r & 1) { int p = (-- r) - n; x.addToVal(leafs[p], p); }
for(l >>= 1, r >>= 1; l < r; l >>= 1, r >>= 1) {
if(l & 1) laziness[l ++] += x;
if(r & 1) laziness[-- r] += x;
}
mergeRange(indices, k);
}
private:
int getIndices(int indices[], int i, int j) const {
int k = 0, l, r;
if(i >= j) return 0;
for(l = (n + i) >> 1, r = (n + j - 1) >> 1; l != r; l >>= 1, r >>= 1) {
indices[k ++] = l;
indices[k ++] = r;
}
for(; l; l >>= 1) indices[k ++] = l;
return k;
}
void propagateRange(int indices[], int k) {
for(int i = k - 1; i >= 0; -- i)
propagate(indices[i]);
}
void mergeRange(int indices[], int k) {
for(int i = 0; i < k; ++ i)
merge(indices[i]);
}
inline void propagate(int i) {
if(i >= n) return;
laziness[i].addToSum(nodes[i], leftpos[i], rightpos[i]);
if(i * 2 < n) {
laziness[i * 2] += laziness[i];
laziness[i * 2 + 1] += laziness[i];
}else {
laziness[i].addToVal(leafs[i * 2 - n], i * 2 - n);
laziness[i].addToVal(leafs[i * 2 + 1 - n], i * 2 + 1 - n);
}
laziness[i] = Laziness();
}
inline void merge(int i) {
if(i >= n) return;
nodes[i] = sum(i * 2) + sum(i * 2 + 1);
}
inline Sum sum(int i) {
propagate(i);
return i < n ? nodes[i] : Sum(leafs[i - n], i - n);
}
};
struct CentroidPathDecomposition {
vector<int> colors, positions; //Vertex -> Color, Vertex -> Offset
vector<int> lengths, parents, branches; //Color -> Int, Color -> Color, Color -> Offset
vector<int> parentnodes, depths; //Vertex -> Vertex, Vertex -> Int
//vector<FenwickTree>??????1??????????
//sortednodes?[lefts[v], rights[v])?v?subtree??????
vector<int> sortednodes, offsets; //Index -> Vertex, Color -> Index
vector<int> lefts, rights; //Vertex -> Index
struct BuildDFSState {
int i, len, parent;
BuildDFSState() { }
BuildDFSState(int i_, int l, int p): i(i_), len(l), parent(p) { }
};
//??????????????????????????
void build(const vector<vi> &g, int root) {
int n = g.size();
colors.assign(n, -1); positions.assign(n, -1);
lengths.clear(); parents.clear(); branches.clear();
parentnodes.assign(n, -1); depths.assign(n, -1);
sortednodes.clear(); offsets.clear();
lefts.assign(n, -1); rights.assign(n, -1);
vector<int> subtreesizes;
measure(g, root, subtreesizes);
typedef BuildDFSState State;
depths[root] = 0;
vector<State> s;
s.push_back(State(root, 0, -1));
while(!s.empty()) {
State t = s.back(); s.pop_back();
int i = t.i, len = t.len;
int index = sortednodes.size();
int color = lengths.size();
if(t.parent == -3) {
rights[i] = index;
continue;
}
if(t.parent != -2) {
assert(parents.size() == color);
parents.push_back(t.parent);
branches.push_back(len);
offsets.push_back(index);
len = 0;
}
colors[i] = color;
positions[i] = len;
lefts[i] = index;
sortednodes.push_back(i);
int maxsize = -1, maxj = -1;
each(j, g[i]) if(colors[*j] == -1) {
if(maxsize < subtreesizes[*j]) {
maxsize = subtreesizes[*j];
maxj = *j;
}
parentnodes[*j] = i;
depths[*j] = depths[i] + 1;
}
s.push_back(State(i, -1, -3));
if(maxj == -1) {
lengths.push_back(len + 1);
}else {
each(j, g[i]) if(colors[*j] == -1 && *j != maxj)
s.push_back(State(*j, len, color));
s.push_back(State(maxj, len + 1, -2));
}
}
}
void get(int v, int &c, int &p) const {
c = colors[v]; p = positions[v];
}
bool go_up(int &c, int &p) const {
p = branches[c]; c = parents[c];
return c != -1;
}
inline const int *nodesBegin(int c) const { return &sortednodes[0] + offsets[c]; }
inline const int *nodesEnd(int c) const { return &sortednodes[0] + offsets[c+1]; }
private:
void measure(const vector<vi> &g, int root, vector<int> &out_subtreesizes) const {
out_subtreesizes.assign(g.size(), -1);
vector<int> s;
s.push_back(root);
while(!s.empty()) {
int i = s.back(); s.pop_back();
if(out_subtreesizes[i] == -2) {
int s = 1;
each(j, g[i]) if(out_subtreesizes[*j] != -2)
s += out_subtreesizes[*j];
out_subtreesizes[i] = s;
}else {
s.push_back(i);
each(j, g[i]) if(out_subtreesizes[*j] == -1)
s.push_back(*j);
out_subtreesizes[i] = -2;
}
}
}
};
int lowest_common_ancestor(const CentroidPathDecomposition &cpd, int x, int y) {
int cx, px, cy, py;
cpd.get(x, cx, px);
cpd.get(y, cy, py);
while(cx != cy) {
if(cpd.depths[*cpd.nodesBegin(cx)] < cpd.depths[*cpd.nodesBegin(cy)])
cpd.go_up(cy, py);
else
cpd.go_up(cx, px);
}
return cpd.nodesBegin(cx)[min(px, py)];
}
int main() {
int N;
scanf("%d", &N);
vector<Val> initval(N);
rep(i, N) {
int a, b;
scanf("%d%d", &a, &b);
initval[i] = LinearExpr(a, b);
}
vector<vi> g(N);
rep(i, N-1) {
int x, y;
scanf("%d%d", &x, &y), -- x, -- y;
g[x].push_back(y);
g[y].push_back(x);
}
CentroidPathDecomposition cpd;
cpd.build(g, 0);
vector<Val> permutatedInitval(N);
rep(i, N)
permutatedInitval[i] = initval[cpd.sortednodes[i]];
SegmentTree segt;
segt.init(permutatedInitval);
vector<pii> path;
int Q;
scanf("%d", &Q);
rep(ii, Q) {
int ty;
scanf("%d", &ty);
if(ty == 1) {
int u, v, a, b;
scanf("%d%d%d%d", &u, &v, &a, &b), -- u, -- v;
Laziness laziness(LinearExpr(a, b));
int w = lowest_common_ancestor(cpd, u, v), wc, wp;
cpd.get(w, wc, wp);
rep(uv, 2) {
int c, p;
cpd.get(uv == 0 ? u : v, c, p);
while(1) {
int top = c == wc ? wp + uv : 0;
int o = cpd.offsets[c], len = cpd.lengths[c];
//???[o + top, o + p]????? (????)
segt.addToRange(o + top, o + p + 1, laziness);
if(c == wc) break;
cpd.go_up(c, p);
}
}
}else if(ty == 2) {
int u, v, x;
scanf("%d%d%d", &u, &v, &x), -- u, -- v;
LinearExpr expr;
int w = lowest_common_ancestor(cpd, u, v), wc, wp;
cpd.get(w, wc, wp);
rep(uv, 2) {
path.clear();
int c, p;
cpd.get(uv == 0 ? u : v, c, p);
while(1) {
int top = c == wc ? wp + uv : 0;
int o = cpd.offsets[c], len = cpd.lengths[c];
//???[o + top, o + p]????? (????)
path.push_back(mp(o + top, o + p));
if(c == wc) break;
cpd.go_up(c, p);
}
if(uv == 0) {
for(int i = 0; i < (int)path.size(); ++ i) {
int top = path[i].first, bottom = path[i].second;
expr += segt.getRange(top, bottom + 1).backward;
}
}else {
for(int i = (int)path.size() - 1; i >= 0; -- i) {
int top = path[i].first, bottom = path[i].second;
expr += segt.getRange(top, bottom + 1).forward;
}
}
}
mint ans = expr.evalute(x);
printf("%dn", ans.get());
}else return 1;
}
return 0;
}
Problem solution in C programming.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct _lnode{
int x;
int w;
struct _lnode *next;
} lnode;
typedef struct _tree{
long long sum[2][2];
long long sum1[2][2];
long long offset1;
long long offset2;
} tree;
#define MOD 1000000007
void insert_edge(int x,int y,int w);
void dfs0(int u);
void dfs1(int u,int c);
void preprocess();
int lca(int a,int b);
void sum(int v,int tl,int tr,int l,int r,tree *t,long long ans[][2],int f);
void range_update(int v,int tl,int tr,int pos1,int pos2,long long o1,long long o2,tree *t);
void merge(long long a[][2],long long b[][2],long long ans[][2]);
void push(int v,int tl,int tr,tree *t);
void range_solve(int x,int y,int a,int b);
int min(int x,int y);
int max(int x,int y);
long long solve(int x,int y,int a);
void one(long long*a,int SIZE);
void mul(long long*a,long long*b,int SIZE);
void powm(long long*a,int n,long long*res,int SIZE);
int N,cn,A[100000],B[100000],level[100000],DP[18][100000],subtree_size[100000],special[100000],node_chain[100000],node_idx[100000],chain_head[100000],chain_len[100000]={0};
lnode *table[100000]={0};
tree *chain[100000];
int main(){
int Q,x,y,a,b,i;
scanf("%d",&N);
for(i=0;i<N;i++)
scanf("%d%d",A+i,B+i);
for(i=0;i<N-1;i++){
scanf("%d%d",&x,&y);
insert_edge(x-1,y-1,1);
}
preprocess();
scanf("%d",&Q);
while(Q--){
scanf("%d",&x);
switch(x){
case 1:
scanf("%d%d%d%d",&x,&y,&a,&b);
range_solve(x-1,y-1,a,b);
break;
default:
scanf("%d%d%d",&x,&y,&a);
printf("%lldn",solve(x-1,y-1,a));
}
}
return 0;
}
void insert_edge(int x,int y,int w){
lnode *t=malloc(sizeof(lnode));
t->x=y;
t->w=w;
t->next=table[x];
table[x]=t;
t=malloc(sizeof(lnode));
t->x=x;
t->w=w;
t->next=table[y];
table[y]=t;
return;
}
void dfs0(int u){
lnode *x;
subtree_size[u]=1;
special[u]=-1;
for(x=table[u];x;x=x->next)
if(x->x!=DP[0][u]){
DP[0][x->x]=u;
level[x->x]=level[u]+1;
dfs0(x->x);
subtree_size[u]+=subtree_size[x->x];
if(special[u]==-1 || subtree_size[x->x]>subtree_size[special[u]])
special[u]=x->x;
}
return;
}
void dfs1(int u,int c){
lnode *x;
node_chain[u]=c;
node_idx[u]=chain_len[c]++;
for(x=table[u];x;x=x->next)
if(x->x!=DP[0][u])
if(x->x==special[u])
dfs1(x->x,c);
else{
chain_head[cn]=x->x;
dfs1(x->x,cn++);
}
return;
}
void preprocess(){
int i,j;
level[0]=0;
DP[0][0]=0;
dfs0(0);
for(i=1;i<18;i++)
for(j=0;j<N;j++)
DP[i][j] = DP[i-1][DP[i-1][j]];
cn=1;
chain_head[0]=0;
dfs1(0,0);
for(i=0;i<cn;i++){
chain[i]=(tree*)malloc(4*chain_len[i]*sizeof(tree));
memset(chain[i],0,4*chain_len[i]*sizeof(tree));
for(j=0;j<4*chain_len[i];j++)
chain[i][j].offset1=chain[i][j].offset2=-1;
}
for(i=0;i<N;i++)
range_update(1,0,chain_len[node_chain[i]]-1,node_idx[i],node_idx[i],A[i],B[i],chain[node_chain[i]]);
return;
}
int lca(int a,int b){
int i;
if(level[a]>level[b]){
i=a;
a=b;
b=i;
}
int d = level[b]-level[a];
for(i=0;i<18;i++)
if(d&(1<<i))
b=DP[i][b];
if(a==b)return a;
for(i=17;i>=0;i--)
if(DP[i][a]!=DP[i][b])
a=DP[i][a],b=DP[i][b];
return DP[0][a];
}
void sum(int v,int tl,int tr,int l,int r,tree *t,long long ans[][2],int f){
long long a[2][2],b[2][2];
push(v,tl,tr,t);
if(l>r){
ans[0][0]=1;
ans[0][1]=0;
ans[1][0]=0;
ans[1][1]=1;
return;
}
if(l==tl && r==tr){
if(f)
memcpy(ans,t[v].sum1,sizeof(t[v].sum1));
else
memcpy(ans,t[v].sum,sizeof(t[v].sum));
return;
}
int tm=(tl+tr)/2;
sum(v*2,tl,tm,l,min(r,tm),t,a,f);
sum(v*2+1,tm+1,tr,max(l,tm+1),r,t,b,f);
if(f)
merge(b,a,ans);
else
merge(a,b,ans);
return;
}
void range_update(int v,int tl,int tr,int pos1,int pos2,long long o1,long long o2,tree *t){
push(v,tl,tr,t);
if(pos2<tl || pos1>tr)
return;
int tm=(tl+tr)/2;
if(pos1<=tl && pos2>=tr){
t[v].offset1=o1;
t[v].offset2=o2;
}
else{
range_update(v*2,tl,tm,pos1,pos2,o1,o2,t);
range_update(v*2+1,tm+1,tr,pos1,pos2,o1,o2,t);
push(v*2,tl,tm,t);
push(v*2+1,tm+1,tr,t);
merge(t[v*2].sum,t[v*2+1].sum,t[v].sum);
merge(t[v*2+1].sum1,t[v*2].sum1,t[v].sum1);
}
return;
}
void merge(long long a[][2],long long b[][2],long long ans[][2]){
ans[0][0]=(a[0][0]*b[0][0]+a[0][1]*b[1][0])%MOD;
ans[0][1]=(a[0][0]*b[0][1]+a[0][1]*b[1][1])%MOD;
ans[1][0]=(a[1][0]*b[0][0]+a[1][1]*b[1][0])%MOD;
ans[1][1]=(a[1][0]*b[0][1]+a[1][1]*b[1][1])%MOD;
return;
}
void push(int v,int tl,int tr,tree *t){
long long a[2][2];
if(t[v].offset1==-1 || t[v].offset2==-1)
return;
a[0][0]=t[v].offset1;
a[0][1]=t[v].offset2;
a[1][0]=0;
a[1][1]=1;
powm(&a[0][0],tr-tl+1,&t[v].sum[0][0],2);
memcpy(t[v].sum1,t[v].sum,sizeof(t[v].sum));
if(tl!=tr){
t[v*2].offset1=t[v*2+1].offset1=t[v].offset1;
t[v*2].offset2=t[v*2+1].offset2=t[v].offset2;
}
t[v].offset1=t[v].offset2=-1;
return;
}
void range_solve(int x,int y,int a,int b){
int ca=lca(x,y);
while(node_chain[x]!=node_chain[ca]){
range_update(1,0,chain_len[node_chain[x]]-1,0,node_idx[x],a,b,chain[node_chain[x]]);
x=DP[0][chain_head[node_chain[x]]];
}
range_update(1,0,chain_len[node_chain[x]]-1,node_idx[ca],node_idx[x],a,b,chain[node_chain[x]]);
while(node_chain[y]!=node_chain[ca]){
range_update(1,0,chain_len[node_chain[y]]-1,0,node_idx[y],a,b,chain[node_chain[y]]);
y=DP[0][chain_head[node_chain[y]]];
}
if(node_idx[y]!=node_idx[ca])
range_update(1,0,chain_len[node_chain[y]]-1,node_idx[ca]+1,node_idx[y],a,b,chain[node_chain[y]]);
return;
}
int min(int x,int y){
return (x<y)?x:y;
}
int max(int x,int y){
return (x>y)?x:y;
}
long long solve(int x,int y,int a){
int ca=lca(x,y);
long long t1[2][2],t2[2][2]={1,0,0,1},t3[2][2],ans[2][2];
while(node_chain[x]!=node_chain[ca]){
sum(1,0,chain_len[node_chain[x]]-1,0,node_idx[x],chain[node_chain[x]],t1,0);
memcpy(t3,t2,sizeof(t2));
merge(t1,t3,t2);
x=DP[0][chain_head[node_chain[x]]];
}
sum(1,0,chain_len[node_chain[x]]-1,node_idx[ca],node_idx[x],chain[node_chain[x]],t1,0);
memcpy(t3,t2,sizeof(t2));
merge(t1,t3,ans);
t2[0][0]=1;
t2[0][1]=0;
t2[1][0]=0;
t2[1][1]=1;
while(node_chain[y]!=node_chain[ca]){
sum(1,0,chain_len[node_chain[y]]-1,0,node_idx[y],chain[node_chain[y]],t1,1);
memcpy(t3,t2,sizeof(t2));
merge(t3,t1,t2);
y=DP[0][chain_head[node_chain[y]]];
}
if(node_idx[y]!=node_idx[ca]){
sum(1,0,chain_len[node_chain[y]]-1,node_idx[ca]+1,node_idx[y],chain[node_chain[y]],t1,1);
memcpy(t3,t2,sizeof(t2));
merge(t3,t1,t2);
}
merge(t2,ans,t1);
return (a*t1[0][0]+t1[0][1])%MOD;
}
void one(long long*a,int SIZE){
int i,j;
for (i = 0; i < SIZE; i++)
for (j = 0; j < SIZE; j++)
a[i*SIZE+j] = (i == j);
return;
}
void mul(long long*a,long long*b,int SIZE){
int i,j,k;
long long res[SIZE][SIZE];
for(i=0;i<SIZE;i++)
for(j=0;j<SIZE;j++)
res[i][j]=0;
for (i = 0; i < SIZE; i++)
for (j = 0; j < SIZE; j++)
for (k = 0; k < SIZE; k++)
res[i][j] = (res[i][j]+a[i*SIZE+k] * b[k*SIZE+j])%MOD;
for (i = 0; i < SIZE; i++)
for (j = 0; j < SIZE; j++)
a[i*SIZE+j] = res[i][j];
return;
}
void powm(long long*a,int n,long long*res,int SIZE){
one(res,SIZE);
while (n > 0) {
if (n % 2 == 0)
{
mul(a, a,SIZE);
n /= 2;
}
else {
mul(res, a,SIZE);
n--;
}
}
}