oj.uz

답안 #647912

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
647912 2022-10-04T14:00:50 Z thorie The Xana coup (BOI21_xanadu) C++17
20 / 100
 1000 ms 12640 KB 
#include "bits/stdc++.h"
using namespace std;

vector<vector<int>> graph;
vector<bool> on;
vector<bool> onCopy;
vector<int> v1;
vector<int> v2;

void toggle(int k) {
    on[k] = !on[k];
    for (int i = 0; i < graph[k].size(); i++) {
        on[graph[k][i]] = !on[graph[k][i]];
    }
}

void dfs(int x, bool y, int from) {
    if (y) {
        v1.push_back(x);
    }
    else {
        v2.push_back(x);
    }
    for (int i = 0; i < graph[x].size(); i++) {
        if (graph[x][i] != from) {
            dfs(graph[x][i], !y, x);
        }
    }
}

int main() {
    int n;
    cin >> n;

    graph.resize(n);
    on.resize(n);

    for (int i = 0; i < n - 1; i++) {
        int a, b;
        cin >> a >> b;
        graph[a - 1].push_back(b - 1);
        graph[b - 1].push_back(a - 1);
    }

    for (int i = 0; i < n; i++) {
        bool a;
        cin >> a;
        on[i] = a;
    }

    onCopy = on;

    dfs(0, false, -1);

    if (v1.size() > v2.size()) {
        swap(v1, v2);
    }

    int m = INT_MAX;

    for (int i = 0; i < 1 << v1.size(); i++) {
        int cnt = 0;

        for (int j = 0; j < v1.size(); j++) {
            if (i & 1 << j) {
                toggle(v1[j]);
                cnt++;
            }
        }

        for (int j = 0; j < v2.size(); j++) {
            if (on[v2[j]]) {
                toggle(v2[j]);
                cnt++;
            }
        }

        bool allFalse = true;
        for (int j = 0; j < v1.size(); j++) {
            if (on[v1[j]]) {
                allFalse = false;
                break;
            }
        }

        if (allFalse) {
            m = min(m, cnt);
        }

        on = onCopy;
    }

    if (m == INT_MAX) {
        cout << "impossible" << endl;
    }
    else {
        cout << m << endl;
    }

    return 0;
}

Compilation message

xanadu.cpp: In function 'void toggle(int)':
xanadu.cpp:12:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |     for (int i = 0; i < graph[k].size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~~~
xanadu.cpp: In function 'void dfs(int, bool, int)':
xanadu.cpp:24:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |     for (int i = 0; i < graph[x].size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~~~
xanadu.cpp: In function 'int main()':
xanadu.cpp:64:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   64 |         for (int j = 0; j < v1.size(); j++) {
      |                         ~~^~~~~~~~~~~
xanadu.cpp:71:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   71 |         for (int j = 0; j < v2.size(); j++) {
      |                         ~~^~~~~~~~~~~
xanadu.cpp:79:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   79 |         for (int j = 0; j < v1.size(); j++) {
      |                         ~~^~~~~~~~~~~

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct

Subtask #2
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 31 ms 212 KB Output is correct
12 Correct 71 ms 296 KB Output is correct
13 Correct 577 ms 284 KB Output is correct
14 Correct 294 ms 300 KB Output is correct
15 Correct 1 ms 300 KB Output is correct
16 Correct 1 ms 212 KB Output is correct

Subtask #3
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Execution timed out 1092 ms 12640 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Execution timed out 1099 ms 12476 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 31 ms 212 KB Output is correct
12 Correct 71 ms 296 KB Output is correct
13 Correct 577 ms 284 KB Output is correct
14 Correct 294 ms 300 KB Output is correct
15 Correct 1 ms 300 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Execution timed out 1092 ms 12640 KB Time limit exceeded
18 Halted 0 ms 0 KB -