oj.uz

Submission #698544

# Submission time Handle Problem Language Result Execution time Memory
698544 2023-02-13T18:32:36 Z _martynas Pipes (BOI13_pipes) C++11
100 / 100
 185 ms 18760 KB 
#include <bits/stdc++.h>

using namespace std;

#define F first
#define S second
#define PB push_back

using ll = long long;
using vi = vector<int>;
using pii = pair<int, int>;

const int MXN = 1e5+5;

int n, m;
ll C[MXN];
vector<pii> adj[MXN];
int degree[MXN];
ll E[5*MXN];
bool visited[MXN];

void dfs(int u, vi &comp) {
    visited[u] = true;
    comp.PB(u);
    for(auto p : adj[u]) {
        int v = p.F;
        if(visited[v] || !degree[v]) continue;
        dfs(v, comp);
    }
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cin >> n >> m;
    for(int i = 1; i <= n; i++) cin >> C[i];
    for(int i = 0; i < m; i++) {
        int a, b; cin >> a >> b;
        adj[a].PB({b, i});
        adj[b].PB({a, i});
    }
    queue<int> Q;
    for(int i = 1; i <= n; i++) {
        degree[i] = adj[i].size();
        if(degree[i] == 1) Q.push(i);
    }
    while(!Q.empty()) {
        int u = Q.front();
        Q.pop();
        degree[u] = 0;
        for(auto p : adj[u]) {
            if(degree[p.F]) {
                // there should only be one v that satisfies this condition
                E[p.S] = C[u];
                degree[p.F]--;
                C[p.F] -= C[u];
                if(degree[p.F] == 1) Q.push(p.F);
            }
        }
    }
    // all remaining vertices should be disjoint cycles of odd length
    for(int i = 1; i <= n; i++) {
        if(degree[i] != 0 && degree[i] != 2) {
            cout << "0\n";
            return 0;
        }
    }
    for(int i = 1; i <= n; i++) {
        if(degree[i] && !visited[i]) {
            vi comp;
            dfs(i, comp);
            cerr << comp.size() << "\n";
            if(comp.size() % 2 == 0) {
                cout << "0\n";
                return 0;
            }
            ll sum = 0;
            for(int u : comp) sum += C[u];
            sum /= 2;
            // keep edge cost between 0 and 1
            for(int u = 2; u < comp.size(); u += 2) {
                sum -= C[comp[u]];
            }
            ll last = 0;
            for(auto p : adj[comp[0]]) {
                if(p.F == comp[1]) {
                    E[p.S] = sum;
                    last = E[p.S];
                }
            }
            for(int u = 1; u < comp.size(); u++) {
                for(auto p : adj[comp[u]]) {
                    if(p.F == comp[(u+1)%comp.size()]) {
                        E[p.S] = C[comp[u]]-last;
                        last = E[p.S];
                    }
                }
            }
        }
    }
    for(int i = 0; i < m; i++) {
        cout << 2*E[i] << "\n";
    }
    return 0;
}
/*
3 2
1 2 1
1 2
2 3

3 3
8 10 12
1 2
2 3
1 3

3 7 5
*/

Compilation message

pipes.cpp: In function 'int main()':
pipes.cpp:81:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   81 |             for(int u = 2; u < comp.size(); u += 2) {
      |                            ~~^~~~~~~~~~~~~
pipes.cpp:91:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   91 |             for(int u = 1; u < comp.size(); u++) {
      |                            ~~^~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 70 ms 10020 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2676 KB Output is correct
7 Correct 2 ms 2624 KB Output is correct
8 Correct 2 ms 2644 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 2 ms 2644 KB Output is correct
11 Correct 2 ms 2772 KB Output is correct
12 Correct 2 ms 2684 KB Output is correct
13 Correct 44 ms 8736 KB Output is correct
14 Correct 68 ms 9612 KB Output is correct
15 Correct 56 ms 9940 KB Output is correct
16 Correct 43 ms 8964 KB Output is correct
17 Correct 53 ms 9980 KB Output is correct
18 Correct 63 ms 9984 KB Output is correct
19 Correct 73 ms 9248 KB Output is correct
20 Correct 2 ms 2676 KB Output is correct
21 Correct 3 ms 2644 KB Output is correct
22 Correct 59 ms 10032 KB Output is correct
23 Correct 56 ms 8632 KB Output is correct
24 Correct 52 ms 10024 KB Output is correct
25 Correct 47 ms 8928 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2684 KB Output is correct
2 Correct 2 ms 2772 KB Output is correct
3 Correct 46 ms 11996 KB Output is correct
4 Correct 51 ms 8860 KB Output is correct
5 Correct 48 ms 9208 KB Output is correct
6 Correct 185 ms 18760 KB Output is correct
7 Correct 1 ms 2644 KB Output is correct
8 Correct 2 ms 2644 KB Output is correct
9 Correct 2 ms 2676 KB Output is correct
10 Correct 2 ms 2644 KB Output is correct
11 Correct 2 ms 2680 KB Output is correct
12 Correct 1 ms 2644 KB Output is correct
13 Correct 2 ms 2644 KB Output is correct
14 Correct 1 ms 2644 KB Output is correct
15 Correct 2 ms 2772 KB Output is correct
16 Correct 2 ms 2772 KB Output is correct
17 Correct 2 ms 2684 KB Output is correct
18 Correct 2 ms 2644 KB Output is correct
19 Correct 2 ms 2688 KB Output is correct
20 Correct 2 ms 2688 KB Output is correct
21 Correct 2 ms 2816 KB Output is correct
22 Correct 2 ms 2772 KB Output is correct
23 Correct 52 ms 11844 KB Output is correct
24 Correct 61 ms 13004 KB Output is correct
25 Correct 44 ms 12040 KB Output is correct
26 Correct 39 ms 8984 KB Output is correct
27 Correct 38 ms 8728 KB Output is correct
28 Correct 45 ms 9444 KB Output is correct
29 Correct 174 ms 16564 KB Output is correct
30 Correct 79 ms 12224 KB Output is correct
31 Correct 62 ms 15008 KB Output is correct
32 Correct 56 ms 11016 KB Output is correct
33 Correct 52 ms 12952 KB Output is correct
34 Correct 54 ms 8856 KB Output is correct
35 Correct 42 ms 8912 KB Output is correct
36 Correct 44 ms 9276 KB Output is correct
37 Correct 143 ms 18724 KB Output is correct
38 Correct 66 ms 12508 KB Output is correct
39 Correct 60 ms 10628 KB Output is correct
40 Correct 69 ms 12844 KB Output is correct
41 Correct 67 ms 14900 KB Output is correct
42 Correct 36 ms 8784 KB Output is correct
43 Correct 38 ms 8696 KB Output is correct
44 Correct 51 ms 9164 KB Output is correct
45 Correct 150 ms 16588 KB Output is correct
46 Correct 59 ms 11892 KB Output is correct
47 Correct 61 ms 12836 KB Output is correct
48 Correct 67 ms 14788 KB Output is correct
49 Correct 61 ms 10112 KB Output is correct
50 Correct 60 ms 8960 KB Output is correct
51 Correct 45 ms 9164 KB Output is correct
52 Correct 37 ms 8780 KB Output is correct
53 Correct 129 ms 16508 KB Output is correct
54 Correct 60 ms 11912 KB Output is correct