oj.uz

Submission #950509

# Submission time Handle Problem Language Result Execution time Memory
950509 2024-03-20T11:31:28 Z phoenix0423 Pipes (BOI13_pipes) C++17
100 / 100
 128 ms 52000 KB 
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
#define fastio ios::sync_with_stdio(false), cin.tie(0)
#define pb push_back
#define eb emplace_back
#define f first
#define s second
#define int long long 
const int maxn = 5e5 + 5;
int n, m;
vector<pll> adj[maxn];
int ans[maxn], val[maxn], deg[maxn];

void dfs(int pos, int prev){
    for(auto [x, id] : adj[pos]){
        if(x == prev) continue;
        dfs(x, pos);
        ans[id] = val[x], val[pos] -= val[x];
    }
}

signed main(void){
    fastio;
    cin>>n>>m;
    for(int i = 0; i < n; i++) cin>>val[i];
    for(int i = 0; i < m; i++){
        int a, b;
        cin>>a>>b;
        a--, b--;
        adj[a].eb(b, i);
        adj[b].eb(a, i);
        deg[a] ++, deg[b] ++;
    }
    if(m > n){
        cout<<0<<"\n";
        return 0; 
    }
    queue<int> q;
    for(int i = 0; i < n; i++) if(deg[i] == 1) q.push(i);
    while(!q.empty()){
        int pos = q.front(); q.pop();
        deg[pos] = 0;
        for(auto [x, id] : adj[pos]){
            if(!deg[x]) continue;
            ans[id] = val[pos], val[x] -= val[pos];
            deg[x] --;
            if(deg[x] == 1) q.push(x);
        }
    }
    if(m == n - 1){
        for(int i = 0; i < m; i++) cout<<ans[i] * 2<<"\n";
        return 0;
    }
    int st = 0;
    for(int i = 0; i < n; i++){
        if(deg[i] == 2){
            st = i;
            break;
        }
    }
    int len = 0;
    vector<int> vis(n);
    vector<int> cyc;
    while(!vis[st]){
        vis[st] = 1;
        cyc.pb(st);
        for(auto [x, id] : adj[st]){
            if(!vis[x] && deg[x] == 2){
                st = x;
                break;
            }
        }
    }
    if(cyc.size() % 2 == 0){
        cout<<0<<"\n";
        return 0;
    }
    int ttl = 0;
    for(int i = 1; i < cyc.size(); i++){
        ttl += val[cyc[i]] * (i % 2 ? 1 : -1);
    }
    int a = (ttl + val[cyc[0]]) / 2;
    for(int i = 0; i < cyc.size(); i++){
        for(auto [x, id] : adj[cyc[i]]){
            if(x != cyc[(i + 1) % cyc.size()]) continue;
            ans[id] = a;
            a = val[x] - a;
        }
    }
    for(int i = 0; i < m; i++) cout<<ans[i] * 2<<"\n";
}

Compilation message

pipes.cpp: In function 'int main()':
pipes.cpp:81:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   81 |     for(int i = 1; i < cyc.size(); i++){
      |                    ~~^~~~~~~~~~~~
pipes.cpp:85:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   85 |     for(int i = 0; i < cyc.size(); i++){
      |                    ~~^~~~~~~~~~~~
pipes.cpp:63:9: warning: unused variable 'len' [-Wunused-variable]
   63 |     int len = 0;
      |         ^~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 17500 KB Output is correct
2 Correct 4 ms 17500 KB Output is correct
3 Correct 4 ms 17588 KB Output is correct
4 Correct 45 ms 31292 KB Output is correct
5 Correct 3 ms 17496 KB Output is correct
6 Correct 4 ms 17500 KB Output is correct
7 Correct 4 ms 17496 KB Output is correct
8 Correct 4 ms 17500 KB Output is correct
9 Correct 4 ms 17620 KB Output is correct
10 Correct 4 ms 17500 KB Output is correct
11 Correct 5 ms 17500 KB Output is correct
12 Correct 4 ms 17500 KB Output is correct
13 Correct 35 ms 29780 KB Output is correct
14 Correct 50 ms 31324 KB Output is correct
15 Correct 44 ms 31316 KB Output is correct
16 Correct 37 ms 30292 KB Output is correct
17 Correct 45 ms 31288 KB Output is correct
18 Correct 44 ms 31312 KB Output is correct
19 Correct 44 ms 31060 KB Output is correct
20 Correct 4 ms 17496 KB Output is correct
21 Correct 4 ms 17500 KB Output is correct
22 Correct 45 ms 31408 KB Output is correct
23 Correct 35 ms 29784 KB Output is correct
24 Correct 45 ms 31312 KB Output is correct
25 Correct 37 ms 30028 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 17500 KB Output is correct
2 Correct 4 ms 17592 KB Output is correct
3 Correct 42 ms 31704 KB Output is correct
4 Correct 33 ms 26564 KB Output is correct
5 Correct 32 ms 26192 KB Output is correct
6 Correct 128 ms 51944 KB Output is correct
7 Correct 4 ms 17500 KB Output is correct
8 Correct 4 ms 17500 KB Output is correct
9 Correct 4 ms 17496 KB Output is correct
10 Correct 4 ms 15452 KB Output is correct
11 Correct 3 ms 15448 KB Output is correct
12 Correct 3 ms 15452 KB Output is correct
13 Correct 3 ms 15452 KB Output is correct
14 Correct 4 ms 17500 KB Output is correct
15 Correct 4 ms 17548 KB Output is correct
16 Correct 4 ms 17500 KB Output is correct
17 Correct 4 ms 17600 KB Output is correct
18 Correct 3 ms 15452 KB Output is correct
19 Correct 3 ms 15540 KB Output is correct
20 Correct 3 ms 15452 KB Output is correct
21 Correct 4 ms 15708 KB Output is correct
22 Correct 4 ms 17500 KB Output is correct
23 Correct 40 ms 30932 KB Output is correct
24 Correct 47 ms 32588 KB Output is correct
25 Correct 39 ms 31696 KB Output is correct
26 Correct 34 ms 26704 KB Output is correct
27 Correct 34 ms 26448 KB Output is correct
28 Correct 43 ms 26956 KB Output is correct
29 Correct 105 ms 45388 KB Output is correct
30 Correct 47 ms 31968 KB Output is correct
31 Correct 50 ms 32524 KB Output is correct
32 Correct 47 ms 32204 KB Output is correct
33 Correct 42 ms 32208 KB Output is correct
34 Correct 37 ms 26460 KB Output is correct
35 Correct 34 ms 26512 KB Output is correct
36 Correct 33 ms 26512 KB Output is correct
37 Correct 126 ms 52000 KB Output is correct
38 Correct 48 ms 32456 KB Output is correct
39 Correct 45 ms 32080 KB Output is correct
40 Correct 47 ms 32460 KB Output is correct
41 Correct 41 ms 32456 KB Output is correct
42 Correct 34 ms 26500 KB Output is correct
43 Correct 35 ms 26452 KB Output is correct
44 Correct 38 ms 26580 KB Output is correct
45 Correct 103 ms 48844 KB Output is correct
46 Correct 47 ms 32176 KB Output is correct
47 Correct 46 ms 32460 KB Output is correct
48 Correct 50 ms 32708 KB Output is correct
49 Correct 37 ms 31312 KB Output is correct
50 Correct 33 ms 26448 KB Output is correct
51 Correct 33 ms 26452 KB Output is correct
52 Correct 33 ms 26268 KB Output is correct
53 Correct 110 ms 47996 KB Output is correct
54 Correct 54 ms 32184 KB Output is correct