Submission #1117619

#	Time	Username	Problem	Language	Result	Execution time	Memory
1117619		vjudge1	Paprike (COI18_paprike)	C++17	24 / 100	80 ms	12884 KiB

paprike

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define ld double


const int INF = 1e18;
const int mod = 12345;
const int sz = 1e6 + 5;

int n , k , dp[sz];
vector < vector < int > > adj;
vector < bool > vis(sz , false);
int ans = 0 , sum = 0 , summ = 0;

void dfs(int v){
    vis[v] = 1;
    summ += dp[v];
    sum += dp[v];
    if(sum > k){
        ans++;
        sum = dp[v];
    }
    for(int u : adj[v]){
        if(!vis[u])
        dfs(u);
    }
}

signed main()
{
   ios_base::sync_with_stdio(0);
   cin.tie(0);
   cin >> n >> k;
   adj.resize(n + 1);
   for(int i = 1;i <= n;i++) cin >> dp[i];
   int u[n] , v[n];
   for(int i = 0;i < n - 1;i++){
        cin >> u[i] >> v[i];
        adj[u[i]].push_back(v[i]);
        adj[v[i]].push_back(u[i]);
   }
   if(n <= 15)
   {
   int cav = INF;
   for(int bit = 0;bit < pow(2 , n) - 1;bit++){
        vis.assign(sz , false);
        adj.clear();
        adj.resize(n + 1);
        int cnt = 0;
        for(int i = 0;i < n - 1;i++){
            if((1 << i) & bit){
                adj[u[i]].push_back(v[i]);
                adj[v[i]].push_back(u[i]);
            }
            else{
                cnt++;
            }
        }
        int tot[2];
        tot[0] = tot[1] = 0;
        for(int i = 1;i <= n;i++){
            if(!vis[i]){
                tot[0]++;
                dfs(i);
                if(k >= summ) tot[1]++;
                summ = 0;
            }
        }
        if(tot[1] == tot[0]){
            cav = min(cav , cnt);
        }
   }
   cout << cav << endl;
   return 0;
   }
   adj.clear();
   adj.resize(n + 1);
   for(int i = 0;i < n - 1;i++){
        cin >> u[i] >> v[i];
        adj[u[i]].push_back(v[i]);
        adj[v[i]].push_back(u[i]);
   }
   dfs(1);
   cout << ans << endl;
}

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 0 / 27
• Subtask 4: 0 / 49