Freshman's Database

input/code.cpp: In function 'int main()':
input/code.cpp:8:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&n);
                 ^
input/code.cpp:9:47: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   for(i=0;i<n;++i)scanf("%d",&g[i].p),--g[i].p;
                                               ^

#include <stdio.h>
struct{
  int p;
  int v;
} g[1010101];
int main(){
  int n,i,j,cnt=0;
  scanf("%d",&n);
  for(i=0;i<n;++i)scanf("%d",&g[i].p),--g[i].p;
  for(i=0;i<n;){
    if(g[i++].v)continue;
    j=i-1;
lp: if(g[j].v==i)goto elp;
    if(g[j].v)continue;
    g[j].v=i;
    j=g[j].p;
    goto lp;
elp:++cnt;
  }
  printf("%d\n",cnt);
  return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED