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Submission #197520

# Submission time Handle Problem Language Result Execution time Memory
197520 2020-01-21T13:30:26 Z handlename Forensic (NOI12_forensic) C++17
25 / 25
 5 ms 1404 KB 
#include <bits/stdc++.h>
using namespace std;
int n,arr[20001];
bool vis[20001],vis2[20001];
int maxi[20001];
vector<int> brr;
bool loop;
void dfs(int cur){
    if (cur==-1) return;
    if (vis[cur]){
        loop=true;
        return;
    }
    vis[cur]=true;
    maxi[cur]=0;
    brr.push_back(cur);
    dfs(arr[cur]);
}
int dfs2(int cur){
    if (cur==-1) return 0;
    if ((vis[cur] && loop) || cur==0) return -1e9;
    if (maxi[cur]!=-1) return maxi[cur];
    if (vis2[cur]) return -1e9;
    vis2[cur]=true;
    maxi[cur]=dfs2(arr[cur])+1;
    return maxi[cur];
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin>>n;
    for (int i=0;i<n;i++) cin>>arr[i];
    if (arr[0]==0){
        cout<<1;
        return 0;
    }
    memset(maxi,-1,sizeof(maxi));
    dfs(0);
    int ans=0;
    for (int i=0;i<n;i++){
        if (!vis[i]){
            ans=max(ans,dfs2(i));
        }
    }
    cout<<brr.size()+ans;
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 380 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 504 KB Output is correct
5 Correct 2 ms 376 KB Output is correct

Subtask #2
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 3 ms 428 KB Output is correct
3 Correct 3 ms 376 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 3 ms 504 KB Output is correct

Subtask #3
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 504 KB Output is correct
2 Correct 2 ms 504 KB Output is correct
3 Correct 2 ms 504 KB Output is correct
4 Correct 2 ms 504 KB Output is correct
5 Correct 3 ms 504 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 376 KB Output is correct
2 Correct 4 ms 632 KB Output is correct
3 Correct 4 ms 632 KB Output is correct
4 Correct 5 ms 1404 KB Output is correct
5 Correct 3 ms 760 KB Output is correct