oj.uz

Submission #244297

# Submission time Handle Problem Language Result Execution time Memory
244297 2020-07-03T14:21:09 Z pit4h Olympic Bus (JOI20_ho_t4) C++14
0 / 100
 153 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]);

		long long 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]);
		}
		replace_edge = max(0LL, replace_edge - c[i]);
		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]);
				}
			}
		}

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

		path[0] = min(path[0], replace_edge + G[p][v[i]] + c[i] + d[i] + G[u[i]][q]);

		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 69 ms 2936 KB Output is correct
2 Correct 20 ms 2816 KB Output is correct
3 Correct 79 ms 2936 KB Output is correct
4 Correct 90 ms 2936 KB Output is correct
5 Correct 6 ms 768 KB Output is correct
6 Correct 27 ms 2944 KB Output is correct
7 Correct 4 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 86 ms 2936 KB Output is correct
11 Correct 84 ms 2940 KB Output is correct
12 Correct 89 ms 3064 KB Output is correct
13 Incorrect 42 ms 2944 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 153 ms 4088 KB Output is correct
2 Correct 148 ms 4088 KB Output is correct
3 Correct 150 ms 4124 KB Output is correct
4 Correct 76 ms 2944 KB Output is correct
5 Correct 63 ms 2936 KB Output is correct
6 Correct 33 ms 2944 KB Output is correct
7 Correct 17 ms 2944 KB Output is correct
8 Correct 4 ms 384 KB Output is correct
9 Incorrect 89 ms 4216 KB Output isn't correct
10 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 70 ms 2848 KB Output is correct
2 Correct 34 ms 2816 KB Output is correct
3 Correct 129 ms 3936 KB Output is correct
4 Correct 27 ms 2816 KB Output is correct
5 Correct 139 ms 4192 KB Output is correct
6 Correct 4 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Incorrect 92 ms 3964 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 69 ms 2936 KB Output is correct
2 Correct 20 ms 2816 KB Output is correct
3 Correct 79 ms 2936 KB Output is correct
4 Correct 90 ms 2936 KB Output is correct
5 Correct 6 ms 768 KB Output is correct
6 Correct 27 ms 2944 KB Output is correct
7 Correct 4 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 86 ms 2936 KB Output is correct
11 Correct 84 ms 2940 KB Output is correct
12 Correct 89 ms 3064 KB Output is correct
13 Incorrect 42 ms 2944 KB Output isn't correct
14 Halted 0 ms 0 KB -