제출 #828450

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
828450		AkramElOmrani	경주 (Race) (IOI11_race)	C++17	100 / 100	294 ms	69736 KiB

race

#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,avx2,bmi,bmi2,popcnt,lzcnt")
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { os << '{'; string sep; for (const T &x : v) os << sep << x, sep = ", "; return os << '}'; }
 
void dbg_out() { cerr << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cerr << ' ' << H; dbg_out(T...); }
#define dbg(...) cerr << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__);


const int INF = 1e9 + 5;
int ans = INF;
vector<vector<pair<int, int>>> adj;

// {distance, depth}
void dfs(int node, int p, map<int, int>& mp, int& k, int depth, int distance) {
	mp[distance] = depth;
	for(auto[x, w] : adj[node]) {
		if(p == x) continue;
		map<int, int> nxt;
		dfs(x, node, nxt, k, depth + 1, distance + w);
		if(mp.size() < nxt.size()) swap(mp, nxt);
		for(auto&[x, y] : nxt) {
			int new_dist = k + 2 * distance - x;
			if(mp.count(new_dist)) {
				ans = min(ans, mp[new_dist] + y - 2 * depth);
			}
		}
		for(auto&[x, y] : nxt) {
			if(mp.count(x)) {
				mp[x] = min(mp[x], y);
			} else {
				mp[x] = y;
			}
		}
	}
}

int best_path(int n, int k, int H[][2], int L[])
{
	adj.resize(n);
	for(int i = 0; i < n - 1; ++i) {
		adj[H[i][0]].emplace_back(H[i][1], L[i]);
		adj[H[i][1]].emplace_back(H[i][0], L[i]);
	}
	map<int, int> mp;
	dfs(0, -1, mp, k, 0, 0);
	if(ans == INF) {
		return -1;
	}
	return ans;
}

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