Submission #1077476

#	Time	Username	Problem	Language	Result	Execution time	Memory
1077476		hung_nm	Pipes (BOI13_pipes)	C++17	44.07 / 100	138 ms	56912 KiB

pipes

#include <bits/stdc++.h>
#define pb push_back
#define fi first
#define se second
#define pii pair<int, int>
#define pipii pair<int, pair<int, int>>
#define vi vector<int>
#define vpi vector<pair<int, int>>
#define inp(name) if(fopen(name, "r")) freopen(name, "r", stdin);
#define out(name) if(fopen(name, "w")) freopen(name, "w", stdout);
#define int long long
const int N = 1e6 + 5;
const int mod = 1e9 + 7;
using namespace std;
long long n, m, c[N], ans[N];
vpi ad[N];
void dfs(int u, int p)
{
    long long res = 0;
    for(auto [v, pos] : ad[u])
    {
        if(v == p) continue ;
        dfs(v, u);
        ans[pos] = 2 * c[v];
        c[u] += c[v];
    }
}
signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(0);
    cin >> n >> m;
    for(int i = 1; i <= n; ++i)
    {
        cin >> c[i];
    }

    for(int i = 1; i <= m; ++i)
    {
        int u, v;
        cin >> u >> v;
        ad[u].pb({v, i});
        ad[v].pb({u, i});
    }
    if(m != (n-1))
    {
        cout << 0;
        return 0;
    }

    dfs(1, 0);
    for(int i = 1; i <= m; ++i)
    {
        cout << 2*ans[i] << "\n";
    }
    return 0;
}

Compilation message (stderr)

pipes.cpp: In function 'void dfs(long long int, long long int)':
pipes.cpp:19:15: warning: unused variable 'res' [-Wunused-variable]
   19 |     long long res = 0;
      |               ^~~

• Subtask 1: 0 / 30
• Subtask 2: 44.074074074074076 / 70