Submission #2073266

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Source Code Expand

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
#include<queue>
#define mp(x,y) make_pair(x,y)
using namespace std;

const int N=100005;

int n,a[N],deg[N],f[N];
priority_queue<pair<int,int> > que;

int main()
{
    scanf("%d",&n);
    for (int i=2;i<=n;i++) scanf("%d",&a[i]),deg[a[i]]++;
    int h=0;
    for (int i=1;i<=n;i++) if (!deg[i]) que.push(mp(0,i));
    while (!que.empty())
    {
        int x=que.top().second;que.pop();
        f[a[x]]=max(f[a[x]],f[x])+1;
        deg[a[x]]--;
        if (!deg[a[x]]) que.push(mp(-f[a[x]],a[x]));
    }
    printf("%d",f[1]);
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:17:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&n);
                   ^
./Main.cpp:18:57: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     for (int i=2;i<=n;i++) scanf("%d",&a[i]),deg[a[i]]++;
                                                         ^

Judge Result