제출 #1300881

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1300881		trandangquang	Power Plant (JOI20_power)	C++20	100 / 100	73 ms	26296 KiB

power

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

#define foru(i,a,b) for(int i=(a); i<=(b); ++i)
#define ford(i,a,b) for(int i=(a); i>=(b); --i)
#define rep(i,a) for(int i=0; i<(a); ++i)
#define sz(a) (int)(a).size()
#define all(a) (a).begin(),(a).end()
#define bit(s,i) (((s)>>(i))&1)
#define ii pair<int,int>
#define vi vector<int>
#define vii vector<ii>
#define fi first
#define se second
#define ll long long
#define eb emplace_back
#define pb push_back
#define __builtin_popcount __builtin_popcountll
#define _ << " " <<

template <class X, class Y> bool maxi(X &x, Y y){return x<y?x=y,true:false;}
template <class X, class Y> bool mini(X &x, Y y){return x>y?x=y,true:false;}

const int N=2e5+5;

int n,dp[N],res; /// dp[i]: o tren i co 1 thg bat
vi adj[N];
string s;

void dfs(int u, int p=-1){
    for(int v:adj[u]) if(v!=p){
        dfs(v,u);
        dp[u]+=dp[v];
        res=max(res, dp[v]+(s[u]=='1'));
    }
    if(s[u]=='1') dp[u]=max(dp[u]-1,1);
    res=max(res, dp[u]);
}

void solve(){
    cin>>n;
    rep(i,n-1){
        int u,v; cin>>u>>v;
        adj[u].eb(v); adj[v].eb(u);
    }
    cin>>s;
    s=" "+s;

    dfs(1);
    cout<<res<<'\n';
}

int32_t main(){
    #define task "test"
    if(fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    cin.tie(0)->sync_with_stdio(0);

    int tc=1; //cin>>tc;
    foru(i,1,tc){
        solve();
    }
}

컴파일 시 표준 에러 (stderr) 메시지

power.cpp: In function 'int32_t main()':
power.cpp:56:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
power.cpp:57:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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