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Submission #244280

# Submission time Handle Problem Language Result Execution time Memory
244280 2020-07-03T13:18:22 Z pit4h Olympic Bus (JOI20_ho_t4) C++14
0 / 100
 159 ms 4216 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;
		
		path[0] = min(path[0], skipt[v[i]][u[i]][p==n] + c[i] + skip[u[i]][v[i]][p==1]);

		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 76 ms 2944 KB Output is correct
2 Correct 21 ms 2944 KB Output is correct
3 Correct 88 ms 2936 KB Output is correct
4 Correct 87 ms 3064 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 448 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 5 ms 384 KB Output is correct
10 Correct 92 ms 2944 KB Output is correct
11 Correct 96 ms 2936 KB Output is correct
12 Correct 92 ms 2976 KB Output is correct
13 Incorrect 44 ms 3068 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 158 ms 4088 KB Output is correct
2 Correct 158 ms 4088 KB Output is correct
3 Correct 159 ms 4088 KB Output is correct
4 Correct 86 ms 2936 KB Output is correct
5 Correct 70 ms 2944 KB Output is correct
6 Correct 36 ms 2944 KB Output is correct
7 Correct 16 ms 2944 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Incorrect 88 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 2960 KB Output is correct
2 Correct 37 ms 2936 KB Output is correct
3 Correct 129 ms 3832 KB Output is correct
4 Correct 30 ms 2944 KB Output is correct
5 Correct 145 ms 4216 KB Output is correct
6 Correct 4 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Incorrect 93 ms 4216 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 76 ms 2944 KB Output is correct
2 Correct 21 ms 2944 KB Output is correct
3 Correct 88 ms 2936 KB Output is correct
4 Correct 87 ms 3064 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 448 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 5 ms 384 KB Output is correct
10 Correct 92 ms 2944 KB Output is correct
11 Correct 96 ms 2936 KB Output is correct
12 Correct 92 ms 2976 KB Output is correct
13 Incorrect 44 ms 3068 KB Output isn't correct
14 Halted 0 ms 0 KB -