oj.uz

Submission #244344

# Submission time Handle Problem Language Result Execution time Memory
244344 2020-07-03T16:36:52 Z pit4h Olympic Bus (JOI20_ho_t4) C++14
5 / 100
 285 ms 2552 KB 
#include<bits/stdc++.h>
using namespace std;

const int N = 201, M = 5e4+1;
const int  INF = 3e8+1;
int n, m, u[M], v[M];
int c[M], d[M];
int G[N][N], W[N][N], E[N][N][2];
int 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<int, 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<int, 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];
				}
			}
		}
	}
}

int Dist(int U, bool q, int V) {
	if(!q && U == 1) return 0;
	if(q && U == n) return 0;
	int res = INF;
	for(int i=1; i<=n; ++i) {
		if(i != U && i != V) {
			res = min(res, W[U][i] + skip[i][U][q]);	
		}
	}
	return res;
}

int DistT(int U, bool q, int V) {
	if(!q && U == 1) return 0;
	if(q && U == n) return 0;
	int res = INF;
	for(int i=1; i<=n; ++i) {
		if(i != U && i != V) {
			res = min(res, W[i][U] + skipt[i][U][q]);	
		}
	}
	return res;
}

int solve(int p, int q) {

	int ans = INF;

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

		int path[2] = {0, 0};
// skipt[v[i]][u[i]][p==1]


		path[1] = DistT(v[i], p==1, u[i]) + c[i] + d[i] + Dist(u[i], p==n, v[i]);
		path[0] = INF;
		
		path[0] = min(path[0], DistT(v[i], p==n, u[i]) + c[i] + Dist(u[i], p==1, v[i]));
		
		

		int replace_edge = INF;
		if(E[u[i]][v[i]][0] != c[i]) {
			replace_edge = E[u[i]][v[i]][0];
			path[0] = min(path[0], G[p][u[i]] + E[u[i]][v[i]][0] + G[v[i]][q]);
		}
		else {
			replace_edge = E[u[i]][v[i]][1];
			path[0] = min(path[0], G[p][u[i]] + E[u[i]][v[i]][1] + G[v[i]][q]);
		}
		if(replace_edge < INF) replace_edge = max(0, replace_edge - c[i]);
		if(G[p][u[i]] + c[i] + G[v[i]][q] > G[p][q]) path[0] = min(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]);
				}
			}
		}
		
		path[0] = min(path[0], replace_edge + G[p][v[i]] + c[i] + G[u[i]][q]);

		path[1] = min(path[1], replace_edge + G[q][v[i]] + c[i] + d[i] + G[u[i]][p]);


		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);

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

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 71 ms 1664 KB Output is correct
2 Correct 19 ms 1664 KB Output is correct
3 Correct 78 ms 1656 KB Output is correct
4 Correct 78 ms 1656 KB Output is correct
5 Correct 6 ms 640 KB Output is correct
6 Correct 30 ms 1664 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 87 ms 1656 KB Output is correct
11 Correct 86 ms 1656 KB Output is correct
12 Correct 91 ms 1784 KB Output is correct
13 Correct 43 ms 1664 KB Output is correct
14 Correct 61 ms 1664 KB Output is correct
15 Correct 62 ms 1664 KB Output is correct
16 Correct 64 ms 1656 KB Output is correct

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 282 ms 2552 KB Output is correct
2 Correct 269 ms 2424 KB Output is correct
3 Correct 285 ms 2424 KB Output is correct
4 Correct 83 ms 1656 KB Output is correct
5 Correct 66 ms 1656 KB Output is correct
6 Correct 33 ms 1664 KB Output is correct
7 Correct 17 ms 1664 KB Output is correct
8 Incorrect 4 ms 384 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 74 ms 1664 KB Output is correct
2 Correct 33 ms 1664 KB Output is correct
3 Correct 224 ms 2280 KB Output is correct
4 Correct 27 ms 1664 KB Output is correct
5 Correct 252 ms 2424 KB Output is correct
6 Correct 6 ms 384 KB Output is correct
7 Correct 4 ms 384 KB Output is correct
8 Correct 231 ms 2424 KB Output is correct
9 Correct 223 ms 2552 KB Output is correct
10 Correct 254 ms 2552 KB Output is correct
11 Correct 246 ms 2424 KB Output is correct
12 Correct 245 ms 2424 KB Output is correct
13 Incorrect 5 ms 384 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 71 ms 1664 KB Output is correct
2 Correct 19 ms 1664 KB Output is correct
3 Correct 78 ms 1656 KB Output is correct
4 Correct 78 ms 1656 KB Output is correct
5 Correct 6 ms 640 KB Output is correct
6 Correct 30 ms 1664 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 87 ms 1656 KB Output is correct
11 Correct 86 ms 1656 KB Output is correct
12 Correct 91 ms 1784 KB Output is correct
13 Correct 43 ms 1664 KB Output is correct
14 Correct 61 ms 1664 KB Output is correct
15 Correct 62 ms 1664 KB Output is correct
16 Correct 64 ms 1656 KB Output is correct
17 Correct 282 ms 2552 KB Output is correct
18 Correct 269 ms 2424 KB Output is correct
19 Correct 285 ms 2424 KB Output is correct
20 Correct 83 ms 1656 KB Output is correct
21 Correct 66 ms 1656 KB Output is correct
22 Correct 33 ms 1664 KB Output is correct
23 Correct 17 ms 1664 KB Output is correct
24 Incorrect 4 ms 384 KB Output isn't correct
25 Halted 0 ms 0 KB -