Submission #885117

#	Time	Username	Problem	Language	Result	Execution time	Memory
885117		12345678	Pipes (BOI13_pipes)	C++17	74.07 / 100	148 ms	39796 KiB

pipes

#include <bits/stdc++.h>

using namespace std;

#define ll long long

const int nx=5e5+5;
int n, m, h[nx], u, v, sz, res[nx], vs[nx], lvl[nx], f;
vector<pair<int, int>> d[nx];

void dfs(int u, int p, int idx)
{
    vs[u]=1; lvl[u]=lvl[p]+1;
    for (auto [v, id]:d[u]) 
    {
        if (v==p) continue;
        if (!vs[v]) dfs(v, u, id);
        else if ((lvl[u]-lvl[v]+1)%2==0) f=1;
    }
    if (idx==-1) return;
    res[idx]=2*h[u];
    h[p]-=h[u];
}

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n>>m;
    for (int i=1; i<=n; i++) cin>>h[i];
    for (int i=1; i<=m; i++) cin>>u>>v, d[u].push_back({v, i}), d[v].push_back({u, i});
    dfs(1, 1, -1);
    if (m>n||f)
    {
        cout<<0;
        return 0;
    }
    for (int i=1; i<n; i++) cout<<res[i]<<'\n';
}

• Subtask 1: 30 / 30
• Subtask 2: 44.074074074074076 / 70