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Submission #244292

# Submission time Handle Problem Language Result Execution time Memory
244292 2020-07-03T14:08:03 Z pit4h Olympic Bus (JOI20_ho_t4) C++14
0 / 100
 162 ms 4092 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], skipt[u[i]][v[i]][p==n] + E[u[i]][v[i]][0] + skip[v[i]][u[i]][p==1]);
		}
		else {
			path[0] = min(path[0], skipt[u[i]][v[i]][p==n] + E[u[i]][v[i]][1] + skip[v[i]][u[i]][p==1]);
		}
		if(G[p][u[i]] + c[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 79 ms 3064 KB Output is correct
2 Correct 21 ms 2944 KB Output is correct
3 Correct 83 ms 2936 KB Output is correct
4 Correct 84 ms 2944 KB Output is correct
5 Correct 6 ms 768 KB Output is correct
6 Correct 29 ms 2816 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 5 ms 384 KB Output is correct
10 Correct 94 ms 2964 KB Output is correct
11 Correct 92 ms 2936 KB Output is correct
12 Incorrect 97 ms 2936 KB Output isn't correct
13 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 156 ms 4088 KB Output is correct
2 Correct 159 ms 4088 KB Output is correct
3 Correct 162 ms 4092 KB Output is correct
4 Correct 86 ms 2936 KB Output is correct
5 Correct 81 ms 2936 KB Output is correct
6 Correct 38 ms 2936 KB Output is correct
7 Correct 17 ms 2816 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 75 ms 2944 KB Output is correct
2 Correct 36 ms 2936 KB Output is correct
3 Correct 100 ms 3960 KB Output is correct
4 Correct 30 ms 2944 KB Output is correct
5 Correct 96 ms 4088 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Incorrect 67 ms 4088 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 79 ms 3064 KB Output is correct
2 Correct 21 ms 2944 KB Output is correct
3 Correct 83 ms 2936 KB Output is correct
4 Correct 84 ms 2944 KB Output is correct
5 Correct 6 ms 768 KB Output is correct
6 Correct 29 ms 2816 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 5 ms 384 KB Output is correct
10 Correct 94 ms 2964 KB Output is correct
11 Correct 92 ms 2936 KB Output is correct
12 Incorrect 97 ms 2936 KB Output isn't correct
13 Halted 0 ms 0 KB -