제출 #869930

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
869930		PagodePaiva	The Xana coup (BOI21_xanadu)	C++17	20 / 100	1079 ms	23088 KiB

xanadu

#include<bits/stdc++.h>
#define N 100010
#define inf 1e6

using namespace std;

int n;
vector <int> g[N];
int v[N];
int dp[N][2][2];

void solve(int node, int p, int ap, int app){
    vector <int> vl;
    int sum = 0;
    if(ap == 1) sum++;

    for(auto x : g[node]){
        if(x == p) continue;
        solve(x, node, 0, ap);
        solve(x, node, 1, ap);
        vl.push_back(-dp[x][0][ap] + dp[x][1][ap]);
        sum += dp[x][0][ap];
    }

    int valor = v[node] + ap + app;
    valor %= 2;

    sort(vl.begin(), vl.end());

    if(valor == 0){
        dp[node][ap][app] = min(dp[node][ap][app], sum);
        for(int i = 1;i < vl.size();i += 2){
            sum += vl[i] + vl[i-1];
            dp[node][ap][app] = min(dp[node][ap][app], sum);
        }

        return;
    }

    else{
        if(vl.size() == 0) return;
        sum += vl[0];
        dp[node][ap][app] = min(dp[node][ap][app], sum);

        for(int i = 2;i < vl.size();i += 2){
            sum += vl[i] + vl[i-1];
            dp[node][ap][app] = min(dp[node][ap][app], sum);
        }

        return;
    }
}

int main(){
    cin >> n;

    for(int i = 1;i < n;i++){
        int a, b;
        cin >> a >> b;
        g[a].push_back(b);
        g[b].push_back(a);
    }

    for(int i = 1;i <= n;i++) {dp[i][0][0] = dp[i][1][0] = dp[i][0][1] = dp[i][1][1] = inf; cin >> v[i];}

    solve(1, 1, 0, 0);
    solve(1, 1, 1, 0);

    int res = min(dp[1][1][0], dp[1][0][0]);

    if(res >= N) cout << "impossible\n";
    else cout << res << '\n';

    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

xanadu.cpp: In function 'void solve(int, int, int, int)':
xanadu.cpp:32:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |         for(int i = 1;i < vl.size();i += 2){
      |                       ~~^~~~~~~~~~~
xanadu.cpp:45:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |         for(int i = 2;i < vl.size();i += 2){
      |                       ~~^~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 0 / 10
• Subtask 4: 0 / 40
• Subtask 5: 0 / 30