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Submission #244278

# Submission time Handle Problem Language Result Execution time Memory
244278 2020-07-03T13:11:29 Z pit4h Olympic Bus (JOI20_ho_t4) C++14
0 / 100
 155 ms 4204 KB 
#include<bits/stdc++.h>
using namespace std;

const int N = 201, M = 5e4+1;
const long long INF = 1e12+1;
int n, m, u[M], v[M];
long long c[M], d[M];
long long G[N][N], W[N][N], E[N][N][2];
long long skip[N][N][2], skipt[N][N][2]; // 0 -> (n, 1), 1 -> (1, n)

void calculate_skip(int p, int q) {
	for(int i=1; i<=n; ++i) {
		for(int j=1; j<=n; ++j) {
			skip[i][j][p==1] = INF;
		}
	}
	//calc skip here

	for(int k=1; k<=n; ++k) {
		if(k==q) continue;
		vector<bool> vis(n+1);
		vis[k] = 1;
		priority_queue<pair<long long, int>> Q;
		Q.push({0, q});
		skip[q][k][p==1] = 0;
		while(Q.size()) {
			auto cur = Q.top();
			cur.first *= -1;
			Q.pop();
			if(vis[cur.second]) continue;
			vis[cur.second] = 1;

			for(int i=1; i<=n; ++i) {
				if(i==k) continue;
				if(skip[i][k][p==1] > cur.first + W[i][cur.second]) {
					Q.push({-(cur.first + W[i][cur.second]), i});
					skip[i][k][p==1] = cur.first + W[i][cur.second];
				}
			}
		}
	}

	for(int i=1; i<=n; ++i) {
		for(int j=1; j<=n; ++j) {
			skipt[i][j][p==1] = INF;
		}
	}
	//calc skip here

	for(int k=1; k<=n; ++k) {
		if(k==q) continue;
		vector<bool> vis(n+1);
		vis[k] = 1;
		priority_queue<pair<long long, int>> Q;
		Q.push({0, q});
		skipt[q][k][p==1] = 0;
		while(Q.size()) {
			auto cur = Q.top();
			cur.first *= -1;
			Q.pop();
			if(vis[cur.second]) continue;
			vis[cur.second] = 1;

			for(int i=1; i<=n; ++i) {
				if(i==k) continue;
				if(skipt[i][k][p==1] > cur.first + W[cur.second][i]) {
					Q.push({-(cur.first + W[cur.second][i]), i});
					skipt[i][k][p==1] = cur.first + W[cur.second][i];
				}
			}
		}
	}
}

long long solve(int p, int q) {

	long long ans = INF;

	for(int i=0; i<m; ++i) {

		long long path[2] = {0, 0};
// skipt[v[i]][u[i]][p==1]
		path[1] = skipt[v[i]][u[i]][p==1] + c[i] + d[i] + skip[u[i]][v[i]][p==n];
		path[0] = INF;
		
		if(E[u[i]][v[i]][0] != c[i]) {
			path[0] = min(path[0], G[p][u[i]] + E[u[i]][v[i]][0] + G[v[i]][q]);
		}
		else {
			path[0] = min(path[0], G[p][u[i]] + E[u[i]][v[i]][1] + G[v[i]][q]);
		}
		if(G[p][u[i]] + W[u[i]][v[i]] + G[v[i]][q] > G[p][q]) path[0] = G[p][q];

		else {
			path[0] = min(path[0], skip[p][u[i]][p==1]);
			for(int k=1; k<=n; ++k) {
				if(k != u[i] && k != v[i]) {
					path[0] = min(path[0], G[p][u[i]] + W[u[i]][k] + skip[k][u[i]][p==1]);
				}
			}
		}
		ans = min(ans, path[0] + path[1]);
	}
	return ans;
}

int main() {

	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	cin>>n>>m;

	for(int i=1; i<=n; ++i) {
		for(int j=1; j<=n; ++j) {
			G[i][j] = INF;
			W[i][j] = INF;
			E[i][j][0] = E[i][j][1] = INF;
		}
		G[i][i] = 0;
	}

	for(int i=0; i<m; ++i) {
		cin>>u[i]>>v[i]>>c[i]>>d[i];
		G[u[i]][v[i]] = min(G[u[i]][v[i]], c[i]);
		W[u[i]][v[i]] = min(W[u[i]][v[i]], c[i]);
		if(E[u[i]][v[i]][0] > c[i]) {
			E[u[i]][v[i]][1] = E[u[i]][v[i]][0];
			E[u[i]][v[i]][0] = c[i];
		}
		else if(E[u[i]][v[i]][1] > c[i]) {
			E[u[i]][v[i]][1] = c[i];
		}
	}

	for(int k=1; k<=n; ++k) {
		for(int i=1; i<=n; ++i) {
			for(int j=1; j<=n; ++j) {
				G[i][j] = min(G[i][j], G[i][k] + G[k][j]);	
			}
		}
	}
	
	calculate_skip(1, n);
	calculate_skip(n, 1);

	long long ans = min({G[1][n]+G[n][1], solve(1, n), solve(n, 1)});
	if(ans >= INF) cout<<-1;
	else cout<<ans;
}

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 80 ms 3096 KB Output is correct
2 Correct 21 ms 2944 KB Output is correct
3 Correct 82 ms 2936 KB Output is correct
4 Correct 84 ms 2936 KB Output is correct
5 Correct 6 ms 768 KB Output is correct
6 Correct 28 ms 2936 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 4 ms 384 KB Output is correct
9 Correct 5 ms 384 KB Output is correct
10 Correct 97 ms 2844 KB Output is correct
11 Correct 95 ms 2936 KB Output is correct
12 Correct 92 ms 2960 KB Output is correct
13 Incorrect 46 ms 2936 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 155 ms 4088 KB Output is correct
2 Correct 150 ms 4088 KB Output is correct
3 Correct 155 ms 4088 KB Output is correct
4 Correct 92 ms 3064 KB Output is correct
5 Correct 72 ms 2944 KB Output is correct
6 Correct 35 ms 2944 KB Output is correct
7 Correct 16 ms 2944 KB Output is correct
8 Correct 4 ms 384 KB Output is correct
9 Incorrect 85 ms 4088 KB Output isn't correct
10 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 82 ms 2944 KB Output is correct
2 Correct 37 ms 2936 KB Output is correct
3 Correct 122 ms 3832 KB Output is correct
4 Correct 31 ms 2944 KB Output is correct
5 Correct 133 ms 4092 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 4 ms 384 KB Output is correct
8 Incorrect 94 ms 4204 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 80 ms 3096 KB Output is correct
2 Correct 21 ms 2944 KB Output is correct
3 Correct 82 ms 2936 KB Output is correct
4 Correct 84 ms 2936 KB Output is correct
5 Correct 6 ms 768 KB Output is correct
6 Correct 28 ms 2936 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 4 ms 384 KB Output is correct
9 Correct 5 ms 384 KB Output is correct
10 Correct 97 ms 2844 KB Output is correct
11 Correct 95 ms 2936 KB Output is correct
12 Correct 92 ms 2960 KB Output is correct
13 Incorrect 46 ms 2936 KB Output isn't correct
14 Halted 0 ms 0 KB -