Submission #520211

#	Time	Username	Problem	Language	Result	Execution time	Memory
520211		sofapuden	Islands (IOI08_islands)	C++14	27 / 100	1036 ms	131076 KiB

islands

#include<bits/stdc++.h>

using namespace std;

typedef long long ll;

ll mx = 0, bes = 0;
vector<vector<array<ll,2>>> gr;
vector<int> vis;

void dfs(int x, set<int> &s, ll dis){
    vis[x] = 1;
    s.insert(x);
    if(dis > mx){
        mx = dis;
        bes = x;
    }
    for(auto y : gr[x]){
        if(!s.count(y[0]))dfs(y[0],s,dis+y[1]);
    }
    s.erase(x);
}

int main()
{
    int n; cin >> n;
    gr.resize(n);
    vis.resize(n,0);
    for(int i = 0; i < n; ++i){
        ll a, b; cin >> a >> b;
        a--;
        gr[i].push_back({a,b});
        gr[a].push_back({i,b});
    }
    ll ans = 0;
    for(int i = 0; i < n; ++i){
        if(!vis[i]){
            mx = 0;
            set<int> s;
            dfs(i,s,0);
            dfs(bes,s,0);
            dfs(bes,s,0);
            ans+=mx;
        }
    }
    cout << ans << '\n';
}

• Subtask 1: 27 / 33
• Subtask 2: 0 / 3
• Subtask 3: 0 / 4
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10