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Submission #302726

# Submission time Handle Problem Language Result Execution time Memory
302726 2020-09-19T05:46:42 Z Nodir_Bobiev Aesthetic (NOI20_aesthetic) C++17
60 / 100
 580 ms 38644 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 > 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 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 546 ms 31584 KB Output is correct
2 Correct 548 ms 31908 KB Output is correct
3 Correct 535 ms 31352 KB Output is correct
4 Correct 530 ms 31352 KB Output is correct
5 Correct 533 ms 31352 KB Output is correct
6 Correct 543 ms 32032 KB Output is correct
7 Correct 550 ms 31864 KB Output is correct
8 Correct 580 ms 32120 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 557 ms 31992 KB Output is correct
2 Correct 555 ms 31568 KB Output is correct
3 Correct 553 ms 31608 KB Output is correct
4 Correct 573 ms 31992 KB Output is correct
5 Correct 549 ms 31480 KB Output is correct
6 Correct 545 ms 31608 KB Output is correct
7 Correct 563 ms 31672 KB Output is correct
8 Correct 551 ms 31864 KB Output is correct

Subtask #5
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 484 ms 28596 KB Output is correct
2 Correct 198 ms 32760 KB Output is correct
3 Correct 266 ms 32120 KB Output is correct
4 Correct 286 ms 32120 KB Output is correct
5 Correct 274 ms 32376 KB Output is correct
6 Correct 265 ms 32376 KB Output is correct
7 Correct 276 ms 32376 KB Output is correct
8 Correct 273 ms 32504 KB Output is correct
9 Correct 264 ms 32120 KB Output is correct
10 Correct 287 ms 32504 KB Output is correct
11 Correct 267 ms 32284 KB Output is correct
12 Correct 459 ms 28700 KB Output is correct
13 Correct 263 ms 32248 KB Output is correct
14 Correct 144 ms 36716 KB Output is correct
15 Correct 146 ms 36856 KB Output is correct
16 Correct 448 ms 28504 KB Output is correct
17 Correct 452 ms 28088 KB Output is correct
18 Correct 445 ms 28516 KB Output is correct
19 Correct 201 ms 32760 KB Output is correct
20 Correct 202 ms 32760 KB Output is correct
21 Correct 203 ms 32760 KB Output is correct
22 Correct 201 ms 32760 KB Output is correct

Subtask #6
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 484 ms 28596 KB Output is correct
2 Correct 198 ms 32760 KB Output is correct
3 Correct 266 ms 32120 KB Output is correct
4 Correct 286 ms 32120 KB Output is correct
5 Correct 274 ms 32376 KB Output is correct
6 Correct 265 ms 32376 KB Output is correct
7 Correct 276 ms 32376 KB Output is correct
8 Correct 273 ms 32504 KB Output is correct
9 Correct 264 ms 32120 KB Output is correct
10 Correct 287 ms 32504 KB Output is correct
11 Correct 267 ms 32284 KB Output is correct
12 Correct 459 ms 28700 KB Output is correct
13 Correct 263 ms 32248 KB Output is correct
14 Correct 144 ms 36716 KB Output is correct
15 Correct 146 ms 36856 KB Output is correct
16 Correct 448 ms 28504 KB Output is correct
17 Correct 452 ms 28088 KB Output is correct
18 Correct 445 ms 28516 KB Output is correct
19 Correct 201 ms 32760 KB Output is correct
20 Correct 202 ms 32760 KB Output is correct
21 Correct 203 ms 32760 KB Output is correct
22 Correct 201 ms 32760 KB Output is correct
23 Correct 502 ms 29616 KB Output is correct
24 Correct 259 ms 32760 KB Output is correct
25 Correct 255 ms 27384 KB Output is correct
26 Correct 266 ms 26744 KB Output is correct
27 Correct 259 ms 26744 KB Output is correct
28 Correct 261 ms 27512 KB Output is correct
29 Correct 244 ms 26744 KB Output is correct
30 Correct 251 ms 27128 KB Output is correct
31 Correct 255 ms 27128 KB Output is correct
32 Correct 249 ms 26872 KB Output is correct
33 Correct 263 ms 27272 KB Output is correct
34 Correct 503 ms 28672 KB Output is correct
35 Correct 267 ms 27000 KB Output is correct
36 Correct 166 ms 38644 KB Output is correct
37 Correct 172 ms 38584 KB Output is correct
38 Correct 507 ms 29304 KB Output is correct
39 Correct 493 ms 28896 KB Output is correct
40 Correct 512 ms 29752 KB Output is correct
41 Correct 249 ms 33016 KB Output is correct
42 Correct 248 ms 32888 KB Output is correct
43 Correct 249 ms 32916 KB Output is correct
44 Correct 252 ms 32888 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 -