Is Palindrome - NUMPLIN.cpp

// https://www.codechef.com/INPRG01/problems/NUMPLIN
#include <bits/stdc++.h>

#define fi          first
#define se          second
#define pb          push_back
#define mp          make_pair
#define ll          long long
#define pll         pair<long, long>
#define vll         vector<long long>
#define inf         1e18
#define range(a,b)	substr(a,b-a+1)
#define FIO         ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)

using namespace std;

int main()
{
    FIO;

    #ifndef ONLINE_JUDGE
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #endif

    string s;
    cin >> s;
    bool flag = true;
    for (int i = 0; i < s.size() / 2; i++) {
        if (s[i] != s[s.size() - 1 - i])
            flag = false;
    }
    if (flag)
        cout << "YES\n";
    else
        cout << "NO\n";

    return 0;
}