HackerEarth Group Range problem solution

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define si(x) scanf("%d", &x)
#define sc(x) scanf("%c", &x)
#define sl(x) scanf("%lld", &x)
#define pl(x) printf("%lldn", x)
#define pi(x) printf("%dn", x)
#define gu getchar_unlocked
#define pu putchar_unlocked
#define setbits __builtin_popcountll
#define pb push_back
#define mp make_pair
#define MOD 1000000007
#define speed ios::sync_with_stdio(false)

int parent[2 * 100005];
int size[2 * 100005];
int group_min[2 * 100005];
int group_max[2 * 100005];
int arr[2 * 100005];


void setupDS(int n){
    for(int i = 1; i <= n; i++){
        parent[i] = i;
        size[i] = 1;
        group_min[i] = arr[i];
        group_max[i] = arr[i];
    }
}

int rootDS(int A){
    int num = A;
    while(parent[num] != num){
        parent[num] = parent[parent[num]];
        num = parent[num];
    }
    return num;
}

void unionDS(int A, int B){
    int rootA = rootDS(A);
    int rootB = rootDS(B);
    if(size[rootA] < size[rootB]){
        parent[rootA] = parent[rootB];
        size[rootB] += size[rootA];
        group_max[rootB] = max(group_max[rootB], group_max[rootA]);
        group_min[rootB] = min(group_min[rootB], group_min[rootA]);
    }
    else{
        parent[rootB] = parent[rootA];
        size[rootA] += size[rootB];
        group_max[rootA] = max(group_max[rootB], group_max[rootA]);
        group_min[rootA] = min(group_min[rootB], group_min[rootA]);
    }
}

int main(){
    int n, i;
    si(n);
    for(i = 1; i <= n; i++){
        si(arr[i]);
    }
    setupDS(n);
    int q;
    si(q);
    while(q--){
        int x, y;
        si(x); si(y);
        if(rootDS(x) == rootDS(y)){
            cout<<group_min[rootDS(x)]<<" "<<group_max[rootDS(x)]<<endl;
        }
        else{
            unionDS(x, y);
            cout<<group_min[rootDS(x)]<<" "<<group_max[rootDS(x)]<<endl;
        }
    }
}