oj.uz

Submission #761791

# Submission time Handle Problem Language Result Execution time Memory
761791 2023-06-20T09:37:38 Z sysia Robot (JOI21_ho_t4) C++17
34 / 100
 3000 ms 61228 KB 
//Sylwia Sapkowska
#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
using namespace std;

void __print(int x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << "'" << x << "'";}
void __print(const char *x) {cerr << '"' << x << '"';}
void __print(const string &x) {cerr << '"' << x << '"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef LOCAL
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif

#define int long long
typedef pair<int, int> T;
const int oo = 1e18, oo2 = 1e9+7, K = 30;
const int mod = 998244353;
typedef tuple<int, int, int> F;

void solve(){
	int n, m; cin >> n >> m;
	vector<vector<F>>g(n+1);
	vector<map<int, int>>dp(n+1), sum(n+1);
	for (int i = 0; i<m; i++){
		int a, b, c, p; cin >> a >> b >> c >> p;
		g[a].emplace_back(b, c, p);
		g[b].emplace_back(a, c, p);
		dp[a][c] = oo;
		dp[b][c] = oo;
		sum[a][c] += p;
		sum[b][c] += p;
	}
	// if (m == 1){
	// 	for (auto [x, c, p]: g[1]){
	// 		if (x == n){
	// 			cout << "0\n";
	// 			return;
	// 		}
	// 	}
	// 	cout << "-1\n";
	// 	return;
	// }
	priority_queue<F, vector<F>, greater<F>>pq;
	pq.push({0, 1, -1});
	//dp[v][c] = min koszt dotarcia do v z uzyciem ostatniej krawedzi c, z wymuszeniem jej zmiany pozniej na sciezce
	//dist[v] = min koszt po prostu dotarcia do v
	//stanow jest O(sum of deg v + n) = O(m + n) ?????
	vector<int>dist(n+1, oo);
	dist[1] = 0;
	while ((int)pq.size()){
		auto [d, v, c] = pq.top(); pq.pop();
		if (c == -1){
			if (dist[v] < d) continue;
			//nie wymuszamy zmiany koloru poprzedniej krawedzi
			for (auto [x, e, p]: g[v]){
				//a) nie zmieniamy koloru krawedzi v---x (czyli nie wymuszamy tez zadnej zmiany)
				int cost1 = sum[v][e] - p;
				if (dist[x] > d + cost1){
					dist[x] = d+cost1;
					pq.push({dist[x], x, -1});
				}
				//b) zmieniamy kolor krawedzi c, ale dalej nie wymuszamy zmiany
				//dirichlet ---> zawsze istnieje kolor na jaki mozemy zmienic
				int cost2 = p;
				if (dist[x] > d + cost2){
					dist[x] = d+cost2;
					pq.push({dist[x], x, -1});
				}
				//c) zmieniamy kolor krawedzi c, z wymuszeniem zmiany na pozniej dla nastepnej krawedzi na sciezce
				int cost3 = 0;
				if (dp[x][e] > d){
					dp[x][e] = d;
					pq.push({d, x, e});
				}
			}
		} else {
			if (dp[v][c] < d) continue;
			//wymuszamy zmiane poprzedniej krawedzi c
			for (auto [x, e, p]: g[v]){
				if (e != c) continue;
				int cost = sum[v][c] - p;
				if (dist[x] > d + cost){
					dist[x] = d+cost; 
					//nie oplaca sie zamieniac dwoch sasiednich krawedzi na optymalnej sciezce z koloru c na jakis inny kolor
					//gdyby tak bylo, to moglibysmy usunac jedna zmiane i miec lepszy wynik
					//wiec teraz nie wymuszamy zmiany koloru c
					pq.push({dist[x], x, -1});
				}
			}
			
		}
	}
	if (dist[n] == oo) cout << "-1\n";
	else cout << dist[n] << "\n";
}

int32_t main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);

	solve();

	return 0;
}

Compilation message

Main.cpp: In function 'void solve()':
Main.cpp:83:9: warning: unused variable 'cost3' [-Wunused-variable]
   83 |     int cost3 = 0;
      |         ^~~~~

Subtask #1
34.0 / 34.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 468 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 3 ms 912 KB Output is correct
10 Correct 3 ms 852 KB Output is correct
11 Correct 2 ms 852 KB Output is correct
12 Correct 1 ms 724 KB Output is correct
13 Correct 2 ms 852 KB Output is correct
14 Correct 3 ms 980 KB Output is correct
15 Correct 2 ms 596 KB Output is correct
16 Correct 2 ms 724 KB Output is correct
17 Correct 2 ms 724 KB Output is correct
18 Correct 1 ms 596 KB Output is correct
19 Correct 2 ms 596 KB Output is correct
20 Correct 1 ms 596 KB Output is correct

Subtask #2
0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 95 ms 19028 KB Output is correct
2 Correct 38 ms 10064 KB Output is correct
3 Correct 100 ms 19640 KB Output is correct
4 Correct 67 ms 13392 KB Output is correct
5 Execution timed out 3067 ms 61228 KB Time limit exceeded
6 Halted 0 ms 0 KB -

Subtask #3
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 468 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 3 ms 912 KB Output is correct
10 Correct 3 ms 852 KB Output is correct
11 Correct 2 ms 852 KB Output is correct
12 Correct 1 ms 724 KB Output is correct
13 Correct 2 ms 852 KB Output is correct
14 Correct 3 ms 980 KB Output is correct
15 Correct 2 ms 596 KB Output is correct
16 Correct 2 ms 724 KB Output is correct
17 Correct 2 ms 724 KB Output is correct
18 Correct 1 ms 596 KB Output is correct
19 Correct 2 ms 596 KB Output is correct
20 Correct 1 ms 596 KB Output is correct
21 Correct 95 ms 19028 KB Output is correct
22 Correct 38 ms 10064 KB Output is correct
23 Correct 100 ms 19640 KB Output is correct
24 Correct 67 ms 13392 KB Output is correct
25 Execution timed out 3067 ms 61228 KB Time limit exceeded
26 Halted 0 ms 0 KB -