제출 #1296233

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1296233		thaibeo123	Power Plant (JOI20_power)	C++20	100 / 100	72 ms	26632 KiB

power

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

#define NAME "A"
#define ll long long
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(), x.end()
#define MASK(x) (1ll << (x))
#define BIT(x, i) (((x) >> (i)) & 1)

const int N = 2e5 + 5;

int n, ans;
int a[N];
int dp[N];
vector<int> g[N];

void dfs(int u, int par) {
    dp[u] = a[u];
    int sum = -a[u];
    for (int v : g[u]) {
        if (v == par) continue;
        dfs(v, u);
        ans = max(ans, dp[v] + a[u]);
        sum += dp[v];
    }
    dp[u] = max(dp[u], sum);
    ans = max(ans, dp[u]);
}

void input() {
    cin >> n;
    for (int i = 1; i < n; i++) {
        int u, v;
        cin >> u >> v;
        g[u].pb(v);
        g[v].pb(u);
    }
    for (int i = 1; i <= n; i++) {
        char x;
        cin >> x;
        a[i] = x - '0';
    }
}

void solve() {
    dfs(1, 0);
    cout << ans;
}

signed main() {
    if (fopen(NAME".INP", "r")) {
        freopen(NAME".INP", "r", stdin);
        freopen(NAME".OUT", "w", stdout);
    }
    cin.tie(0)->sync_with_stdio(0);

    int t = 1;
    //cin >> t;
    while (t--) {
        input();
        solve();
    }

    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

power.cpp: In function 'int main()':
power.cpp:55:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   55 |         freopen(NAME".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
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(NAME".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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