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Submission #301912

# Submission time Handle Problem Language Result Execution time Memory
301912 2020-09-18T09:40:51 Z Nodir_Bobiev Aesthetic (NOI20_aesthetic) C++17
60 / 100
 565 ms 37476 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 = 100000000000000000LL;

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 > 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;
			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 5 ms 7424 KB Output is correct
2 Correct 5 ms 7424 KB Output is correct
3 Incorrect 5 ms 7424 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #2
0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 7424 KB Output is correct
2 Correct 5 ms 7424 KB Output is correct
3 Incorrect 5 ms 7424 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 558 ms 30328 KB Output is correct
2 Correct 561 ms 30584 KB Output is correct
3 Correct 548 ms 30176 KB Output is correct
4 Correct 562 ms 30200 KB Output is correct
5 Correct 545 ms 30412 KB Output is correct
6 Correct 553 ms 30968 KB Output is correct
7 Correct 551 ms 30840 KB Output is correct
8 Correct 557 ms 31080 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 548 ms 30840 KB Output is correct
2 Correct 565 ms 30584 KB Output is correct
3 Correct 549 ms 30584 KB Output is correct
4 Correct 561 ms 30968 KB Output is correct
5 Correct 555 ms 30352 KB Output is correct
6 Correct 537 ms 30584 KB Output is correct
7 Correct 547 ms 30584 KB Output is correct
8 Correct 550 ms 30712 KB Output is correct

Subtask #5
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 475 ms 27480 KB Output is correct
2 Correct 199 ms 31608 KB Output is correct
3 Correct 270 ms 30968 KB Output is correct
4 Correct 265 ms 30968 KB Output is correct
5 Correct 266 ms 31096 KB Output is correct
6 Correct 265 ms 31096 KB Output is correct
7 Correct 267 ms 31096 KB Output is correct
8 Correct 297 ms 31224 KB Output is correct
9 Correct 288 ms 30968 KB Output is correct
10 Correct 269 ms 31352 KB Output is correct
11 Correct 280 ms 31244 KB Output is correct
12 Correct 469 ms 27632 KB Output is correct
13 Correct 278 ms 31224 KB Output is correct
14 Correct 142 ms 35576 KB Output is correct
15 Correct 143 ms 35576 KB Output is correct
16 Correct 471 ms 27460 KB Output is correct
17 Correct 459 ms 26988 KB Output is correct
18 Correct 464 ms 27236 KB Output is correct
19 Correct 206 ms 31612 KB Output is correct
20 Correct 204 ms 31652 KB Output is correct
21 Correct 202 ms 31608 KB Output is correct
22 Correct 203 ms 31640 KB Output is correct

Subtask #6
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 475 ms 27480 KB Output is correct
2 Correct 199 ms 31608 KB Output is correct
3 Correct 270 ms 30968 KB Output is correct
4 Correct 265 ms 30968 KB Output is correct
5 Correct 266 ms 31096 KB Output is correct
6 Correct 265 ms 31096 KB Output is correct
7 Correct 267 ms 31096 KB Output is correct
8 Correct 297 ms 31224 KB Output is correct
9 Correct 288 ms 30968 KB Output is correct
10 Correct 269 ms 31352 KB Output is correct
11 Correct 280 ms 31244 KB Output is correct
12 Correct 469 ms 27632 KB Output is correct
13 Correct 278 ms 31224 KB Output is correct
14 Correct 142 ms 35576 KB Output is correct
15 Correct 143 ms 35576 KB Output is correct
16 Correct 471 ms 27460 KB Output is correct
17 Correct 459 ms 26988 KB Output is correct
18 Correct 464 ms 27236 KB Output is correct
19 Correct 206 ms 31612 KB Output is correct
20 Correct 204 ms 31652 KB Output is correct
21 Correct 202 ms 31608 KB Output is correct
22 Correct 203 ms 31640 KB Output is correct
23 Correct 530 ms 28464 KB Output is correct
24 Correct 251 ms 31608 KB Output is correct
25 Correct 259 ms 26272 KB Output is correct
26 Correct 252 ms 25532 KB Output is correct
27 Correct 263 ms 25648 KB Output is correct
28 Correct 268 ms 26396 KB Output is correct
29 Correct 250 ms 25596 KB Output is correct
30 Correct 265 ms 25936 KB Output is correct
31 Correct 267 ms 26016 KB Output is correct
32 Correct 263 ms 25716 KB Output is correct
33 Correct 263 ms 26104 KB Output is correct
34 Correct 517 ms 27524 KB Output is correct
35 Correct 265 ms 25976 KB Output is correct
36 Correct 174 ms 37424 KB Output is correct
37 Correct 183 ms 37476 KB Output is correct
38 Correct 531 ms 28280 KB Output is correct
39 Correct 513 ms 27468 KB Output is correct
40 Correct 536 ms 28416 KB Output is correct
41 Correct 260 ms 31608 KB Output is correct
42 Correct 256 ms 31608 KB Output is correct
43 Correct 254 ms 31700 KB Output is correct
44 Correct 259 ms 31700 KB Output is correct

Subtask #7
0 / 27.0

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