Submission #890676

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Source Code Expand

#include <stdio.h>
#include <algorithm>
#include <assert.h>
#include <set>
#include <map>
#include <complex>
#include <iostream>
#include <time.h>
#include <stack>
#include <stdlib.h>
#include <memory.h>
#include <bitset>
#include <math.h>
#include <string>
#include <string.h>
#include <queue>
#include <vector>

using namespace std;

const int MaxN = 2e5 + 10;
const int INF = 1e9;
const int MOD = 1e9 + 7;

int n, a[MaxN];

int main() {
//  freopen("input.txt", "r", stdin);
  scanf("%d", &n);
  for (int i = 1; i <= n; ++i) {
    scanf("%d", &a[i]);
  }
  int ans = 0;
  for (int i = 1; i <= n; ++i) {
    if (a[a[i]] == i) {
      ans++;
    }
  }
  cout << ans / 2 << '\n';
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:29:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &n);
                  ^
./Main.cpp:31:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &a[i]);
                       ^

Judge Result