제출 #301024

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
301024		milisav	Power Plant (JOI20_power)	C++14	100 / 100	249 ms	68344 KiB

power

#include<bits/stdc++.h>
#pragma GCC optimize("O3")
#define maxn 2000000
using namespace std;
int n;
vector<int> a[maxn];
char s[maxn];
int dp[maxn];
int ans=0;
void dfs(int u,int p=-1) {
    for(auto v:a[u]) if(v!=p) dfs(v,u);
    int ad=0;
    if(s[u]=='1') ad=1;
    for(auto v:a[u]) if(v!=p) ans=max(ans,dp[v]+ad);
    dp[u]=-ad;
    for(auto v:a[u]) if(v!=p) dp[u]+=dp[v];
    dp[u]=max(dp[u],ad);
    ans=max(ans,dp[u]);
}
int main() {
    int u,v;
    scanf("%d",&n);
    for(int i=0;i<n-1;i++) {
        scanf("%d %d",&u,&v);
        a[u].push_back(v);
        a[v].push_back(u);
    }
    scanf("%s",s+1);
    dfs(1);
    printf("%d",ans);
	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

power.cpp: In function 'int main()':
power.cpp:22:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   22 |     scanf("%d",&n);
      |     ~~~~~^~~~~~~~~
power.cpp:24:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   24 |         scanf("%d %d",&u,&v);
      |         ~~~~~^~~~~~~~~~~~~~~
power.cpp:28:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   28 |     scanf("%s",s+1);
      |     ~~~~~^~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 41 / 41
• Subtask 3: 53 / 53