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Submission #301938

# Submission time Handle Problem Language Result Execution time Memory
301938 2020-09-18T10:07:33 Z Nodir_Bobiev Aesthetic (NOI20_aesthetic) C++17
60 / 100
 587 ms 37552 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;
			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];
    	if( V[i] == U[i] )continue;
    	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 7552 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 7552 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 556 ms 30456 KB Output is correct
2 Correct 576 ms 30712 KB Output is correct
3 Correct 533 ms 30200 KB Output is correct
4 Correct 538 ms 30200 KB Output is correct
5 Correct 564 ms 30328 KB Output is correct
6 Correct 565 ms 30840 KB Output is correct
7 Correct 557 ms 30840 KB Output is correct
8 Correct 587 ms 30968 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 552 ms 30840 KB Output is correct
2 Correct 556 ms 30456 KB Output is correct
3 Correct 555 ms 30456 KB Output is correct
4 Correct 578 ms 30948 KB Output is correct
5 Correct 553 ms 30604 KB Output is correct
6 Correct 537 ms 30456 KB Output is correct
7 Correct 555 ms 30584 KB Output is correct
8 Correct 547 ms 30712 KB Output is correct

Subtask #5
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 454 ms 27480 KB Output is correct
2 Correct 205 ms 31480 KB Output is correct
3 Correct 266 ms 31096 KB Output is correct
4 Correct 266 ms 31096 KB Output is correct
5 Correct 265 ms 31096 KB Output is correct
6 Correct 261 ms 31096 KB Output is correct
7 Correct 269 ms 31288 KB Output is correct
8 Correct 265 ms 31224 KB Output is correct
9 Correct 264 ms 31096 KB Output is correct
10 Correct 294 ms 31440 KB Output is correct
11 Correct 274 ms 31096 KB Output is correct
12 Correct 469 ms 27604 KB Output is correct
13 Correct 276 ms 31116 KB Output is correct
14 Correct 149 ms 35568 KB Output is correct
15 Correct 144 ms 35616 KB Output is correct
16 Correct 478 ms 27476 KB Output is correct
17 Correct 460 ms 27024 KB Output is correct
18 Correct 460 ms 27264 KB Output is correct
19 Correct 199 ms 31736 KB Output is correct
20 Correct 198 ms 31604 KB Output is correct
21 Correct 198 ms 31540 KB Output is correct
22 Correct 199 ms 31736 KB Output is correct

Subtask #6
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 454 ms 27480 KB Output is correct
2 Correct 205 ms 31480 KB Output is correct
3 Correct 266 ms 31096 KB Output is correct
4 Correct 266 ms 31096 KB Output is correct
5 Correct 265 ms 31096 KB Output is correct
6 Correct 261 ms 31096 KB Output is correct
7 Correct 269 ms 31288 KB Output is correct
8 Correct 265 ms 31224 KB Output is correct
9 Correct 264 ms 31096 KB Output is correct
10 Correct 294 ms 31440 KB Output is correct
11 Correct 274 ms 31096 KB Output is correct
12 Correct 469 ms 27604 KB Output is correct
13 Correct 276 ms 31116 KB Output is correct
14 Correct 149 ms 35568 KB Output is correct
15 Correct 144 ms 35616 KB Output is correct
16 Correct 478 ms 27476 KB Output is correct
17 Correct 460 ms 27024 KB Output is correct
18 Correct 460 ms 27264 KB Output is correct
19 Correct 199 ms 31736 KB Output is correct
20 Correct 198 ms 31604 KB Output is correct
21 Correct 198 ms 31540 KB Output is correct
22 Correct 199 ms 31736 KB Output is correct
23 Correct 541 ms 28504 KB Output is correct
24 Correct 250 ms 31608 KB Output is correct
25 Correct 274 ms 26268 KB Output is correct
26 Correct 250 ms 25592 KB Output is correct
27 Correct 254 ms 25592 KB Output is correct
28 Correct 259 ms 26488 KB Output is correct
29 Correct 254 ms 25592 KB Output is correct
30 Correct 279 ms 25976 KB Output is correct
31 Correct 259 ms 26008 KB Output is correct
32 Correct 269 ms 25848 KB Output is correct
33 Correct 274 ms 26232 KB Output is correct
34 Correct 516 ms 27644 KB Output is correct
35 Correct 254 ms 26104 KB Output is correct
36 Correct 164 ms 37552 KB Output is correct
37 Correct 176 ms 37432 KB Output is correct
38 Correct 520 ms 28252 KB Output is correct
39 Correct 518 ms 27448 KB Output is correct
40 Correct 516 ms 28416 KB Output is correct
41 Correct 250 ms 31736 KB Output is correct
42 Correct 259 ms 31736 KB Output is correct
43 Correct 251 ms 31736 KB Output is correct
44 Correct 254 ms 31736 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 7552 KB Output is correct
3 Incorrect 5 ms 7424 KB Output isn't correct
4 Halted 0 ms 0 KB -