oj.uz

Submission #302731

# Submission time Handle Problem Language Result Execution time Memory
302731 2020-09-19T06:06:18 Z Nodir_Bobiev Aesthetic (NOI20_aesthetic) C++17
60 / 100
 558 ms 37820 KB 
/*
+----------------------------------------------------------------+
| In the name of Allah, the most Gracious and the most Merciful. |
+----------------------------------------------------------------+
+------------------------------------------------------+
| Ба номи Худованди беандоза Mеҳрабон ва ниҳоят Бораҳм |
+------------------------------------------------------+
+-----------------------------------------+
| Во имя Аллаха Милостивого, Милосердного |
+-----------------------------------------+
This world is a trial for us
And we know well that we must
Obey the orders from my lord
To avoid all sins and seek reward
*/
# include <bits/stdc++.h>
# define FILE
using namespace std;

const int N = 3e5 + 100;
const long long inf = 1e15;

int n, m, timm, curr, bridge, U[N], V[N], W[N], maxW[N], tin[N], low[N];
long long dist[2][N], within[N], without[N];
vector < int > graph[N];

void bfs( int v, long long *dist ){
	for( int i = 1; i <= n; i ++ ) dist[i] = inf;
	dist[v] = 0;
	priority_queue < pair <long long, int>, vector<pair<long long, int>>, greater<pair<long long, int> > > pq;
	pq.push({0,v});
	while( !pq.empty() ){
		long long  dst; int v; tie(dst, v) = pq.top(); pq.pop();
		if( dst < 0 ) throw;
		if( dst > dist[v] )continue;
		for( auto i: graph[v] ){
			int to = (v == V[i]?U[i]:V[i]);
			if( dist[to] > dist[v] + W[i] ){
				dist[to] = dist[v] + W[i];
				pq.push({dist[to], to});
			}
		}
	}
}
void dfs( int v, int f, int ras ){
	tin[v] = low[v] = ++timm;
	for( auto i: graph[v] ){
		if( without[i] > ras )continue;
		int to = (v==V[i]?U[i]:V[i]);
		if( tin[to] <= curr ){
			dfs(to, v, ras);
			if( low[to] > tin[v] && tin[n] >= tin[to] && within[i] > ras )
				bridge = 1;
			else low[v] = min( low[v], low[to]);
		}else if( to != f ){
			low[v] = min( low[v], tin[to]);
		}
	}
}

bool check( long long ras){
	curr = timm;
	bridge = 0;
	dfs(1, 0, ras);
	//cout << "check " << curr << ' ' << tin[n] << ' ' <<bridge << endl;
	if( tin[n] <= curr) return 0;
	if( bridge )return 0;
	return true;
}

int main(){
    # ifdef FILEs
        freopen( "input.txt", "r", stdin );
        freopen( "output.txt", "w", stdout );
    # endif
    ios_base::sync_with_stdio(false);
    cin >> n >> m;
    for( int i = 1; i <= m; i ++ ){
    	cin >> V[i] >> U[i] >> W[i];
    	graph[V[i]].push_back( i );
    	graph[U[i]].push_back( i );
    }
    for( int i = m-1; i >= 1; i -- ){
    	maxW[i] = max( W[i+1], maxW[i+1]);
    }
    bfs( 1, dist[0]);
    bfs( n, dist[1]);
    for( int i = 1; i <= m; i ++ ){
    	without[i] = min( dist[0][V[i]] + dist[1][U[i]], dist[0][U[i]] + dist[1][V[i]]) + W[i];
    	within[i] = without[i] + maxW[i];
    }
    /*
    for( int i = 1; i <= m; i ++ ){
    	cout << i << ' ' << V[i] <<' ' << U[i] << ' ' << without[i] << ' ' << within[i] <<' ' <<maxW[i]<< endl;
    }cout << endl;
    */
    long long l = dist[0][n]-1, r = dist[0][n] + maxW[1];
    while( r - l > 1 ){
    	long long mid = ( l + r ) >> 1;
    	//cout << l << ' '<< mid << ' ' << r << endl;
    	if( check(mid) )
    		r = mid;
    	else 
    		l = mid;
    }
    cout << r;
    return 0;
}

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 7424 KB Output is correct
2 Correct 5 ms 7516 KB Output is correct
3 Incorrect 6 ms 7296 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #2
0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 7424 KB Output is correct
2 Correct 5 ms 7516 KB Output is correct
3 Incorrect 6 ms 7296 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 557 ms 30456 KB Output is correct
2 Correct 553 ms 30584 KB Output is correct
3 Correct 518 ms 30200 KB Output is correct
4 Correct 519 ms 30300 KB Output is correct
5 Correct 518 ms 30456 KB Output is correct
6 Correct 531 ms 30796 KB Output is correct
7 Correct 553 ms 30968 KB Output is correct
8 Correct 553 ms 30944 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 545 ms 30840 KB Output is correct
2 Correct 550 ms 30524 KB Output is correct
3 Correct 536 ms 30584 KB Output is correct
4 Correct 542 ms 30840 KB Output is correct
5 Correct 528 ms 30456 KB Output is correct
6 Correct 531 ms 30712 KB Output is correct
7 Correct 541 ms 30460 KB Output is correct
8 Correct 558 ms 30712 KB Output is correct

Subtask #5
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 474 ms 27864 KB Output is correct
2 Correct 200 ms 31480 KB Output is correct
3 Correct 262 ms 31040 KB Output is correct
4 Correct 265 ms 30968 KB Output is correct
5 Correct 265 ms 31096 KB Output is correct
6 Correct 266 ms 31124 KB Output is correct
7 Correct 266 ms 31096 KB Output is correct
8 Correct 267 ms 31224 KB Output is correct
9 Correct 261 ms 31096 KB Output is correct
10 Correct 261 ms 31352 KB Output is correct
11 Correct 269 ms 31480 KB Output is correct
12 Correct 448 ms 27900 KB Output is correct
13 Correct 266 ms 31352 KB Output is correct
14 Correct 141 ms 35832 KB Output is correct
15 Correct 142 ms 35832 KB Output is correct
16 Correct 450 ms 27592 KB Output is correct
17 Correct 432 ms 27376 KB Output is correct
18 Correct 444 ms 27540 KB Output is correct
19 Correct 199 ms 31864 KB Output is correct
20 Correct 208 ms 31864 KB Output is correct
21 Correct 204 ms 31864 KB Output is correct
22 Correct 198 ms 31864 KB Output is correct

Subtask #6
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 474 ms 27864 KB Output is correct
2 Correct 200 ms 31480 KB Output is correct
3 Correct 262 ms 31040 KB Output is correct
4 Correct 265 ms 30968 KB Output is correct
5 Correct 265 ms 31096 KB Output is correct
6 Correct 266 ms 31124 KB Output is correct
7 Correct 266 ms 31096 KB Output is correct
8 Correct 267 ms 31224 KB Output is correct
9 Correct 261 ms 31096 KB Output is correct
10 Correct 261 ms 31352 KB Output is correct
11 Correct 269 ms 31480 KB Output is correct
12 Correct 448 ms 27900 KB Output is correct
13 Correct 266 ms 31352 KB Output is correct
14 Correct 141 ms 35832 KB Output is correct
15 Correct 142 ms 35832 KB Output is correct
16 Correct 450 ms 27592 KB Output is correct
17 Correct 432 ms 27376 KB Output is correct
18 Correct 444 ms 27540 KB Output is correct
19 Correct 199 ms 31864 KB Output is correct
20 Correct 208 ms 31864 KB Output is correct
21 Correct 204 ms 31864 KB Output is correct
22 Correct 198 ms 31864 KB Output is correct
23 Correct 513 ms 28804 KB Output is correct
24 Correct 257 ms 31992 KB Output is correct
25 Correct 273 ms 26500 KB Output is correct
26 Correct 247 ms 25848 KB Output is correct
27 Correct 278 ms 25848 KB Output is correct
28 Correct 271 ms 26616 KB Output is correct
29 Correct 257 ms 25848 KB Output is correct
30 Correct 276 ms 26232 KB Output is correct
31 Correct 267 ms 26232 KB Output is correct
32 Correct 256 ms 26104 KB Output is correct
33 Correct 260 ms 26488 KB Output is correct
34 Correct 513 ms 28024 KB Output is correct
35 Correct 253 ms 26232 KB Output is correct
36 Correct 166 ms 37820 KB Output is correct
37 Correct 180 ms 37820 KB Output is correct
38 Correct 497 ms 28516 KB Output is correct
39 Correct 483 ms 27888 KB Output is correct
40 Correct 509 ms 28912 KB Output is correct
41 Correct 252 ms 31992 KB Output is correct
42 Correct 251 ms 31992 KB Output is correct
43 Correct 253 ms 31992 KB Output is correct
44 Correct 251 ms 31992 KB Output is correct

Subtask #7
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 7424 KB Output is correct
2 Correct 5 ms 7516 KB Output is correct
3 Incorrect 6 ms 7296 KB Output isn't correct
4 Halted 0 ms 0 KB -