oj.uz

Submission #861973

# Submission time Handle Problem Language Result Execution time Memory
861973 2023-10-17T09:58:28 Z Trisanu_Das The Xana coup (BOI21_xanadu) C++17
20 / 100
 1000 ms 14032 KB 
#include <bits/stdc++.h>
using namespace std;
 
vector<vector<int>> graph;
vector<bool> on, onCopy;
vector<int> v1, 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\n";
    else cout << m << '\n';
}

Compilation message

xanadu.cpp: In function 'void toggle(int)':
xanadu.cpp:10:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |     for (int i = 0; i < graph[k].size(); i++) on[graph[k][i]] = !on[graph[k][i]];
      |                     ~~^~~~~~~~~~~~~~~~~
xanadu.cpp: In function 'void dfs(int, bool, int)':
xanadu.cpp:16:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |     for (int i = 0; i < graph[x].size(); i++) if (graph[x][i] != from) dfs(graph[x][i], !y, x);
      |                     ~~^~~~~~~~~~~~~~~~~
xanadu.cpp: In function 'int main()':
xanadu.cpp:40:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |         for (int j = 0; j < v1.size(); j++) {
      |                         ~~^~~~~~~~~~~
xanadu.cpp:46:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |         for (int j = 0; j < v2.size(); j++) {
      |                         ~~^~~~~~~~~~~
xanadu.cpp:53:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |         for (int j = 0; j < v1.size(); j++) {
      |                         ~~^~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 444 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 444 KB Output is correct
6 Correct 0 ms 600 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 1 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 21 ms 348 KB Output is correct
12 Correct 47 ms 436 KB Output is correct
13 Correct 376 ms 412 KB Output is correct
14 Correct 177 ms 412 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct

Subtask #3
0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1031 ms 13872 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 40.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1048 ms 14032 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 444 KB Output is correct
6 Correct 0 ms 600 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 1 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 21 ms 348 KB Output is correct
12 Correct 47 ms 436 KB Output is correct
13 Correct 376 ms 412 KB Output is correct
14 Correct 177 ms 412 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Execution timed out 1031 ms 13872 KB Time limit exceeded
18 Halted 0 ms 0 KB -