Palindromi

#include<bits/stdc++.h>
using namespace std;
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define fi first
#define se second
#define pii pair<int,int>
using ll = long long;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    
    string s;
    cin >> s;

    int n = s.size(), ans = 0;
    for (int i = 0; i < n/2; i++) if (s[i] != s[n-1-i]) ans++;

    cout << ans << "\n";
    
    return 0;
}

Test 1 (public)

Verdict: ACCEPTED

Test 2 (public)

Verdict: ACCEPTED

Test 3 (public)

Verdict: ACCEPTED

Test 4 (public)

Verdict: ACCEPTED

Test 5 (public)

Verdict: ACCEPTED

Test 6 (public)

Verdict: ACCEPTED

Test 7 (public)

Verdict: ACCEPTED

Test 8 (public)

Verdict: ACCEPTED

Test 9 (public)

Verdict: ACCEPTED

Test 10 (public)

Verdict: ACCEPTED