HackerEarth Good Subsequences problem solution YASH PAL, 31 July 2024 In this HackerEarth Good Subsequences problem solution You are given a string S consisting of lowercase alphabets. A good subsequence of this string is a subsequence which contains distinct characters only. Determine the number of good subsequences of the maximum possible length modulo 10^9 + 7. In other words, determine the length X of the longest good subsequence and the number of good subsequences of length X modulo 10^9 + 7. HackerEarth Good Subsequences problem solution. #include <bits/stdc++.h>using namespace std; #define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);#define endl "n"#define int long longconst int N=1e5+5;const int MOD=1e9+7;string s;int f[26];int32_t main(){ IOS; int t; cin>>t; while(t--) { int ans=1; cin>>s; for(auto &ch:s) f[ch-'a']++; for(int i=0;i<26;i++) { if(!f[i]) continue; ans*=f[i]; ans%=MOD; } cout<<ans<<endl; } return 0;} Second solution #ifndef _GLIBCXX_NO_ASSERT#include <cassert>#endif#include <cctype>#include <cerrno>#include <cfloat>#include <ciso646>#include <climits>#include <clocale>#include <cmath>#include <csetjmp>#include <csignal>#include <cstdarg>#include <cstddef>#include <cstdio>#include <cstdlib>#include <cstring>#include <ctime>#if __cplusplus >= 201103L#include <ccomplex>#include <cfenv>#include <cinttypes>#include <cstdbool>#include <cstdint>#include <ctgmath>#include <cwchar>#include <cwctype>#endif// C++#include <algorithm>#include <bitset>#include <complex>#include <deque>#include <exception>#include <fstream>#include <functional>#include <iomanip>#include <ios>#include <iosfwd>#include <iostream>#include <istream>#include <iterator>#include <limits>#include <list>#include <locale>#include <map>#include <memory>#include <new>#include <numeric>#include <ostream>#include <queue>#include <set>#include <sstream>#include <stack>#include <stdexcept>#include <streambuf>#include <string>#include <typeinfo>#include <utility>#include <valarray>#include <vector>#if __cplusplus >= 201103L#include <array>#include <atomic>#include <chrono>#include <condition_variable>#include <forward_list>#include <future>#include <initializer_list>#include <mutex>#include <random>#include <ratio>#include <regex>#include <scoped_allocator>#include <system_error>#include <thread>#include <tuple>#include <typeindex>#include <type_traits>#include <unordered_map>#include <unordered_set>#endif#define ll long long#define pb push_back#define mp make_pair#define pii pair<int,int>#define vi vector<int>#define all(a) (a).begin(),(a).end()#define F first#define S second#define sz(x) (int)x.size()#define hell 1000000007#define endl 'n'#define rep(i,a,b) for(int i=a;i<b;i++)using namespace std;string to_string(string s) { return '"' + s + '"';}string to_string(const char* s) { return to_string((string) s);}string to_string(bool b) { return (b ? "true" : "false");}string to_string(char ch) { return string("'")+ch+string("'");}template <typename A, typename B>string to_string(pair<A, B> p) { return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";}template <class InputIterator>string to_string (InputIterator first, InputIterator last) { bool start = true; string res = "{"; while (first!=last) { if (!start) { res += ", "; } start = false; res += to_string(*first); ++first; } res += "}"; return res;}template <typename A>string to_string(A v) { bool first = true; string res = "{"; for (const auto &x : v) { if (!first) { res += ", "; } first = false; res += to_string(x); } res += "}"; return res;}void debug_out() { cerr << endl; }template <typename Head, typename... Tail>void debug_out(Head H, Tail... T) { cerr << " " << to_string(H); debug_out(T...);}template <typename A, typename B>istream& operator>>(istream& input,pair<A,B>& x){ input>>x.F>>x.S; return input;}template <typename A>istream& operator>>(istream& input,vector<A>& x){ for(auto& i:x) input>>i; return input;}#ifdef PRINTERS#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)#else#define debug(...) 42#endiflong long readInt(long long l,long long r,char endd){ long long x=0; int cnt=0; int fi=-1; bool is_neg=false; while(true){ char g=getchar(); if(g=='-'){ assert(fi==-1); is_neg=true; continue; } if('0'<=g && g<='9'){ x*=10; x+=g-'0'; if(cnt==0){ fi=g-'0'; } cnt++; assert(fi!=0 || cnt==1); assert(fi!=0 || is_neg==false); assert(!(cnt>19 || ( cnt==19 && fi>1) )); } else if(g==endd){ assert(cnt>0); if(is_neg){ x= -x; } assert(l<=x && x<=r); return x; } else { debug(int(g)); assert(false); } }}string readString(int l,int r,char endd){ string ret=""; int cnt=0; while(true){ char g=getchar(); if(g==endd){ break; } else if(islower(g)){ cnt++; ret+=g; } else{ assert(false); } } assert(l<=cnt && cnt<=r); return ret;}long long readIntSp(long long l,long long r){ return readInt(l,r,' ');}long long readIntLn(long long l,long long r){ return readInt(l,r,'n');}string readStringLn(int l,int r){ return readString(l,r,'n');}string readStringSp(int l,int r){ return readString(l,r,' ');}void solve(){ int t = readIntLn(1,10); for(int i = 0; i < t; i++){ string s; if(i+1 == t) s = readString(1,100000,EOF); else s = readStringLn(1,100000); map<char,int>m; for(auto i:s){ m[i]++; } ll res = 1; for(auto i:m){ res = (res * i.second)%hell; } cout << res << endl; }}int main(){ solve(); return 0;} coding problems