Submission #890781

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Source Code Expand

#include <bits/stdc++.h>

#define FO(i,a,b) for (int i = (a); i < (b); i++)
#define sz(v) int(v.size())

using namespace std;

int a[100005];
int n;

int main() {
    scanf("%d", &n);
    FO(i,1,n+1) scanf("%d", &a[i]);
    int r = 0;
    FO(i,1,n+1) r += a[a[i]] == i;
    printf("%d\n", r/2);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:12:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
                    ^
./Main.cpp:13:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     FO(i,1,n+1) scanf("%d", &a[i]);
                                   ^

Judge Result