제출 #510194

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
510194		Yazan_Alattar	Islands (IOI08_islands)	C++14	40 / 100	2059 ms	31008 KiB

islands

#include <iostream>
#include <fstream>
#include <vector>
#include <cstring>
#include <algorithm>
#include <set>
#include <map>
#include <queue>
#include <list>
#include <utility>
#include <cmath>
#include <numeric>
#include <assert.h>
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pb push_back
#define endl "\n"
#define all(x) x.begin(), x.end()
const int M = 200007;
const ll inf = 1e18;
const ll mod = 1e9 + 7;
const double pi = acos(-1);
const int dx[] = {1, 0, -1, 0}, dy[] = {0, 1, 0, -1};

vector < pair < int,ll > > adj[M];
ll n, ans, grp[M], mx[M], curgroup;
bool vist[M], on[M];

void connect(int node)
{
    grp[node] = curgroup;
    vist[node] = 1;
    for(auto i : adj[node]){
        if(vist[i.F]) continue;
        connect(i.F);
    }
    return;
}

ll dfs(int node, ll cost)
{
    ll ret = cost;
    on[node] = 1;
    for(auto i : adj[node]){
        if(on[i.F]) continue;
        ret = max(ret, dfs(i.F, cost + i.S));
    }
    on[node] = 0;
    return ret;
}

int main()
{
    ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    cin >> n;
    for(int i = 1; i <= n; ++i){
        ll x, y;
        cin >> x >> y;
        adj[x].pb({i, y});
        adj[i].pb({x, y});
    }
    for(int i = 1; i <= n; ++i){
        curgroup = i;
        if(!grp[i]) connect(i);
        mx[grp[i]] = max(mx[grp[i]], dfs(i, 0));
    }
    for(int i = 1; i <= n; ++i) ans += mx[i];
    cout << ans << endl;
    return 0;
}

• Subtask 1: 33 / 33
• Subtask 2: 3 / 3
• Subtask 3: 4 / 4
• Subtask 4: 0 / 10
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