Submission #881191

#	Time	Username	Problem	Language	Result	Execution time	Memory
881191		Karoot	Race (IOI11_race)	C++17	0 / 100	2 ms	12380 KiB

race

#include <iostream>
#include <cmath>
#include <unordered_map>
#include <map>
#include <set>
#include <queue>
#include <vector>
#include <string>
#include <iomanip>
#include <algorithm>

#define all(x)  (x).begin(), (x).end()
#define rall(x)  (x).rbegin(), (x).rend()

using namespace std;

typedef long long ll;

ll linf = 1e15+1;

inline void scoobydoobydoo(){
    ios::sync_with_stdio(false);
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);
}

const int MAXN = 2e5+1;
bool isVisited[MAXN];
vector<pair<int, int>> adj[MAXN];
bool visited[MAXN];
int subSz[MAXN];
int ans = 1e9+1;
int cnt[MAXN*5];

int subTreeSz(int node, int parent){
    subSz[node] = 1;
    for (auto& e : adj[node]){
        if (e.first != parent && !isVisited[e.first])subSz[node] += subTreeSz(e.first, node);
    }
    return subSz[node];
}

int centroidFind(int node, int parent, int target){
    for (auto& e : adj[node]){
        if (e.first != parent && !isVisited[e.first] && target <= subSz[e.first]){
            return centroidFind(e.first, node, target);
        }
    }
    return node;
}

int vals[MAXN];
int counter = 0;

void cleaning(int node, int parent, int w){
    cnt[w] = -1;
    for (auto& e : adj[node]){
        if (e.first != parent && !isVisited[e.first]){
            cleaning(e.first, node, w+vals[e.second]);
        }
    }
}

void bfs(int node, int parent, int k, int w, bool filling, int depth = 1){
    if (w > k)return;
    if (filling)(cnt[w] == -1 ? cnt[w] = depth : cnt[w] = min(cnt[w], depth));
    else if (cnt[k-w] != -1){
        //cout << node << " " << parent << " " << w << " " << depth << endl;
        //cout << cnt[k-w] << endl;
        ans = min(ans, cnt[k-w]+depth);
    }
    for (auto& e : adj[node]){
        if (e.first != parent && !isVisited[e.first]){
            bfs(e.first, node, k, w + vals[e.second], filling, depth+1);
        }
    }
}


void centroidDecomp(int node, int k){
    node = centroidFind(node, -1, subTreeSz(node, -1)/2);
    isVisited[node] = true;
    //cout << "CENTROID: " << node << endl;
    cleaning(node, node, 0);
    for (auto& e : adj[node]){
        bfs(e.first, node, k, vals[e.second], 0);
        bfs(e.first, node, k, vals[e.second], 1);
    }

    for (auto& e : adj[node]){
        if (!isVisited[e.first])centroidDecomp(e.first, k);
    }
}


int best_path(int N, int K, int H[][2], int L[]){
    for (int i = 0; i <= K; i++){
        cnt[i] = -1;
    }
    for (int i = 0; i < N-1; i++){
        vals[i] = L[i];
        adj[H[i][0]].push_back({H[i][1], i});
        adj[H[i][1]].push_back({H[i][0], i});
    }
    centroidDecomp(0, K);
    return (ans < 1e9 ? ans : -1);
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 12
• Subtask 3: 0 / 22
• Subtask 4: 0 / 57