Submission #1125647

#	Time	Username	Problem	Language	Result	Execution time	Memory
1125647		salmon	Cat Exercise (JOI23_ho_t4)	C++20	31 / 100	2095 ms	31868 KiB

Main

#include <bits/stdc++.h>
using namespace std;

int N;
int lst[200100];
vector<int> adjlst[200100];
int u,v;
bool visited[200100];
int d[200100];

pair<int,int> big(int i, int p, int de){
    pair<int,int> ii = {lst[i],i};
    d[i] = de;

    for(int j : adjlst[i]){
        if(visited[j]) continue;
        if(j == p) continue;
        ii = max(ii, big(j,i, de+1));
    }

    return ii;
}

int solve(int i){
    visited[i] = true;
//printf(" %d",visited[i]);
    int have = -1;
    int ans = 0;

    for(int j : adjlst[i]){
        if(visited[j]) continue;
        have = j;
        pair<int,int> ii = big(j,i,1);
        ans = max(ans,d[ii.second] + solve(ii.second));
    }

    return ans;
}

int main(){

    scanf(" %d",&N);

    int r;

    for(int i = 0; i < N; i++){
        scanf(" %d",&lst[i]);
        if(lst[i] == N) r = i;
        visited[i] = false;
    }

    for(int i = 0; i < N - 1; i++){
        scanf(" %d",&u);
        scanf(" %d",&v);

        u--;
        v--;

        adjlst[u].push_back(v);
        adjlst[v].push_back(u);
    }

    printf("%d\n",solve(r));

}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:42:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |     scanf(" %d",&N);
      |     ~~~~~^~~~~~~~~~
Main.cpp:47:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |         scanf(" %d",&lst[i]);
      |         ~~~~~^~~~~~~~~~~~~~~
Main.cpp:53:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   53 |         scanf(" %d",&u);
      |         ~~~~~^~~~~~~~~~
Main.cpp:54:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   54 |         scanf(" %d",&v);
      |         ~~~~~^~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 7 / 7
• Subtask 4: 10 / 10
• Subtask 5: 0 / 20
• Subtask 6: 0 / 23
• Subtask 7: 0 / 26