Submission #419518

#	Time	Username	Problem	Language	Result	Execution time	Memory
419518		Emin2004	Crocodile's Underground City (IOI11_crocodile)	C++14	46 / 100	4 ms	2892 KiB

crocodile

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

#define ll long long
#define pb push_back
#define pii pair<int, ll>
#define F first
#define S second

const int N = 100005;
const int mod = 1e9+7;

struct edge{
    int from;
    int to;
    ll weight;
};

edge e[N * 10];
set<int> ext;
vector<pii> a[N];
int parent[N], rnk[N], ext_cnt[N];

bool cmp(edge a, edge b) {
    return a.weight < b.weight;
}

int get_par(int a){
    if(parent[a] == a) return a;
    return parent[a] = get_par(parent[a]);
}

void uni(int a, int b){
    if(rnk[a] > rnk[b]) swap(a, b);
    parent[a] = b;
    if(rnk[a] == rnk[b]) rnk[b]++;
}

ll DFS(int node, int par){
    ll mn1 = LONG_MAX, mn2 = LONG_MAX;
    if(ext.find(node) != ext.end()) {
        ext_cnt[node] = 1;
        return 0;
    }
    for(pii i : a[node]){
        if(i.F == par) continue;
        ll cur = DFS(i.F, node);
        if(ext_cnt[i.F] == 0 || cur == LONG_MAX) continue;
        cur += i.S;
        ext_cnt[node] += ext_cnt[i.F];
        if(cur <= mn1){
            mn2 = mn1;
            mn1 = cur;
        }
        else if(cur < mn2) mn2 = cur;
    }
    if(ext_cnt[node] == 0 || mn1 == LONG_MAX || mn2 == LONG_MAX) return LONG_MAX;
    return mn2;
}

int travel_plan(int n, int m, int r[][2], int l[], int k, int p[]){
    for(int i = 0; i < m; i++){
        e[i].from = r[i][0];
        e[i].to = r[i][1];
        e[i].weight = l[i] * 1ll;
    }
    for(int i = 0; i < k; i++) ext.insert(p[i]);
    for(int i = 0; i < n; i++) parent[i] = i;
    sort(e, e + m, cmp);
    for(int i = 0; i < m; i++){
        if(ext.find(e[i].from) != ext.end() || ext.find(e[i].to) != ext.end()) {
            a[e[i].from].pb({e[i].to, e[i].weight});
            a[e[i].to].pb({e[i].from, e[i].weight});
            continue;
        }
        int x = get_par(e[i].from);
        int y = get_par(e[i].to);
        if(x != y){
            uni(x, y);
            a[e[i].from].pb({e[i].to, e[i].weight});
            a[e[i].to].pb({e[i].from, e[i].weight});
        }
    }
    return DFS(0, 0);
}

• Subtask 1: 46 / 46
• Subtask 2: 0 / 43
• Subtask 3: 0 / 11