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답안 #302733

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
302733 2020-09-19T06:15:39 Z Nodir_Bobiev Aesthetic (NOI20_aesthetic) C++17
60 / 100
 551 ms 37560 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]);
    if( dist[0][n] == inf )throw;
    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

# 결과 실행 시간 메모리 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

# 결과 실행 시간 메모리 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

# 결과 실행 시간 메모리 Grader output
1 Correct 543 ms 30500 KB Output is correct
2 Correct 541 ms 30584 KB Output is correct
3 Correct 528 ms 30328 KB Output is correct
4 Correct 532 ms 30328 KB Output is correct
5 Correct 542 ms 30456 KB Output is correct
6 Correct 550 ms 30968 KB Output is correct
7 Correct 545 ms 30840 KB Output is correct
8 Correct 536 ms 30844 KB Output is correct

Subtask #4
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 551 ms 30968 KB Output is correct
2 Correct 549 ms 30456 KB Output is correct
3 Correct 531 ms 30456 KB Output is correct
4 Correct 545 ms 31096 KB Output is correct
5 Correct 524 ms 30328 KB Output is correct
6 Correct 522 ms 30584 KB Output is correct
7 Correct 543 ms 30712 KB Output is correct
8 Correct 531 ms 30588 KB Output is correct

Subtask #5
16.0 / 16.0

# 결과 실행 시간 메모리 Grader output
1 Correct 459 ms 27516 KB Output is correct
2 Correct 198 ms 31456 KB Output is correct
3 Correct 256 ms 30968 KB Output is correct
4 Correct 261 ms 31072 KB Output is correct
5 Correct 261 ms 31224 KB Output is correct
6 Correct 261 ms 31224 KB Output is correct
7 Correct 268 ms 31096 KB Output is correct
8 Correct 273 ms 31208 KB Output is correct
9 Correct 263 ms 30968 KB Output is correct
10 Correct 268 ms 31352 KB Output is correct
11 Correct 260 ms 31224 KB Output is correct
12 Correct 446 ms 27516 KB Output is correct
13 Correct 264 ms 31224 KB Output is correct
14 Correct 146 ms 35576 KB Output is correct
15 Correct 143 ms 35600 KB Output is correct
16 Correct 454 ms 27644 KB Output is correct
17 Correct 437 ms 27244 KB Output is correct
18 Correct 462 ms 27232 KB Output is correct
19 Correct 199 ms 31608 KB Output is correct
20 Correct 199 ms 31608 KB Output is correct
21 Correct 197 ms 31608 KB Output is correct
22 Correct 198 ms 31608 KB Output is correct

Subtask #6
22.0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 459 ms 27516 KB Output is correct
2 Correct 198 ms 31456 KB Output is correct
3 Correct 256 ms 30968 KB Output is correct
4 Correct 261 ms 31072 KB Output is correct
5 Correct 261 ms 31224 KB Output is correct
6 Correct 261 ms 31224 KB Output is correct
7 Correct 268 ms 31096 KB Output is correct
8 Correct 273 ms 31208 KB Output is correct
9 Correct 263 ms 30968 KB Output is correct
10 Correct 268 ms 31352 KB Output is correct
11 Correct 260 ms 31224 KB Output is correct
12 Correct 446 ms 27516 KB Output is correct
13 Correct 264 ms 31224 KB Output is correct
14 Correct 146 ms 35576 KB Output is correct
15 Correct 143 ms 35600 KB Output is correct
16 Correct 454 ms 27644 KB Output is correct
17 Correct 437 ms 27244 KB Output is correct
18 Correct 462 ms 27232 KB Output is correct
19 Correct 199 ms 31608 KB Output is correct
20 Correct 199 ms 31608 KB Output is correct
21 Correct 197 ms 31608 KB Output is correct
22 Correct 198 ms 31608 KB Output is correct
23 Correct 505 ms 28480 KB Output is correct
24 Correct 246 ms 31608 KB Output is correct
25 Correct 257 ms 26360 KB Output is correct
26 Correct 260 ms 25592 KB Output is correct
27 Correct 249 ms 25592 KB Output is correct
28 Correct 248 ms 26492 KB Output is correct
29 Correct 250 ms 25592 KB Output is correct
30 Correct 260 ms 26104 KB Output is correct
31 Correct 251 ms 25976 KB Output is correct
32 Correct 248 ms 25720 KB Output is correct
33 Correct 257 ms 26104 KB Output is correct
34 Correct 487 ms 27836 KB Output is correct
35 Correct 252 ms 25976 KB Output is correct
36 Correct 160 ms 37504 KB Output is correct
37 Correct 175 ms 37560 KB Output is correct
38 Correct 490 ms 28296 KB Output is correct
39 Correct 472 ms 27428 KB Output is correct
40 Correct 485 ms 28596 KB Output is correct
41 Correct 263 ms 31736 KB Output is correct
42 Correct 256 ms 31596 KB Output is correct
43 Correct 253 ms 31608 KB Output is correct
44 Correct 256 ms 31736 KB Output is correct

Subtask #7
0 / 27.0

# 결과 실행 시간 메모리 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 -