oj.uz

답안 #970015

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
970015 2024-04-26T06:09:13 Z lurhx 경주 (Race) (IOI11_race) C++17
0 / 100
 1 ms 2396 KB 
#include "race.h"

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define mp make_pair
#define f first
#define s second
const int inf = 1e9;
vector<vector<pair<int,int>>> edges;
vector<bool> centroids;
vector<int> sizes;
int n,k;
int get_size(int node, int parent = -1) {
    int res = 1;
    for(auto i: edges[node]) {
        if(centroids[i.f] || i.f==parent)continue;
        res+=get_size(i.f,node);
    }
    return sizes[node]=res;
}
int get_centroid(int node,int parent = -1) {
    for(auto i: edges[node]) {
        if(centroids[i.f] || i.f == parent)continue;
        if(sizes[i.f]*2>n)
            return get_centroid(i.f,node);
    }
    return node;
}
map<int,int> dis1,dis2;
void dfs(int node,int val,int times,int parent = -1) {
    if(dis1.find(val)==dis1.end()) {
        dis1[val] = times;
    }else {
        if(dis2.find(val)==dis2.end())
            dis2[val] = times;
        else
            dis2[val] = min(dis2[val],times);
        if(dis2[val]<dis1[val])
            swap(dis2[val],dis1[val]);
    }
    for(auto i: edges[node]) {
        if(i.f==parent || centroids[i.f]) continue;
        dfs(i.f,val+i.s,times+1,node);
    }
}
int solve(int node) {
    dis1.clear();
    dis2.clear();
    //find centroid;
    get_size(node);
    int centroid = get_centroid(node);
    centroids[centroid] = true;
    dfs(centroid,0,0);
    int ans = inf;
    for(auto i: dis1) {
        int need = k-i.f;
        if(need == i.f) {
            if(dis2.find(need)!=dis2.end())
                ans = min(ans,i.s+dis2[need]);
        }else {
            if(dis1.find(need)!=dis1.end())
                ans = min(ans,i.s+dis1[need]);
        }
    }
    for(auto i: edges[centroid]) {
        if(!centroids[i.f])
            ans = min(ans,solve(i.f));
    }
    return ans;
}

int best_path(int N, int K, int H[][2], int L[]){
    n = N;
    k = K;
    edges.resize(n);
    sizes.resize(n);
    centroids.resize(n);
    pair<int,int> in[n];
    int len[n];
    for(int i = 0; i<n-1; i++) {
        in[i].f = H[i][0]; in[i].s = H[i][1]; len[i] = L[i];
        edges[in[i].f].emplace_back(in[i].s,len[i]);
        edges[in[i].s].emplace_back(in[i].f,len[i]);
    }
    auto _ = solve(0);
    if(_ == inf)
        _ =-1;
    return _;
}
/*
int main() {
    cin >> n >> k;
    edges.resize(n);
    sizes.resize(n);
    centroids.resize(n);
    pair<int,int> in[n];
    int len[n];
    for(int i = 0; i<n-1; i++) {
        cin >> in[i].f >> in[i].s >> len[i];
        edges[in[i].f].emplace_back(in[i].s,len[i]);
        edges[in[i].s].emplace_back(in[i].f,len[i]);
    }
    auto _ = solve(0);
    if(_ == inf)
        _ =-1;
    cout << _;
}*/

Subtask #1
0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 1 ms 2396 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 1 ms 2396 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 1 ms 2396 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 57.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 1 ms 2396 KB Output isn't correct
2 Halted 0 ms 0 KB -