The correct, optimal and working solution for programming question sherlock-and-array on hackerrank

/* * Author: Arpit Bhayani * https://arpitbhayani.me */ #include <cmath> #include <cstdio> #include <cstdlib> #include <climits> #include <deque> #include <iostream> #include <list> #include <limits> #include <map> #include <queue> #include <set> #include <stack> #include <vector> #define ll long long #define MIN(a, b) a < b ? a : b #define MAX(a, b) a > b ? a : b using namespace std; int readline(char *str) { int i = 0; char ch; while((ch = getchar()) != '\n') { str[i++] = ch; } str[i] = '\0'; return i; } ll int arr[100010]; int main(int argc, char *argv[]) { int t; scanf("%d", &t); while(t--) { int n; cin >> n; ll int sum = 0; for(int i = 0 ; i < n ; i++) { scanf("%lld", &arr[i]); sum += arr[i]; } ll int lsum = 0, rsum; int i = 0, count = 0; for(i = 1 ; i < n; i++) { lsum += arr[i-1]; rsum = sum - lsum - arr[i]; if(lsum == rsum) { count++; } } if(count || n == 1) { printf("YES\n"); } else { printf("NO\n"); } } return 0; }