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답안 #301883

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
301883 2020-09-18T09:07:45 Z Nodir_Bobiev Aesthetic (NOI20_aesthetic) C++17
60 / 100
 587 ms 41908 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];
    	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

# 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 587 ms 30348 KB Output is correct
2 Correct 561 ms 30756 KB Output is correct
3 Correct 542 ms 30288 KB Output is correct
4 Correct 547 ms 30384 KB Output is correct
5 Correct 533 ms 30272 KB Output is correct
6 Correct 552 ms 30840 KB Output is correct
7 Correct 556 ms 30832 KB Output is correct
8 Correct 562 ms 31004 KB Output is correct

Subtask #4
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 555 ms 30968 KB Output is correct
2 Correct 557 ms 30584 KB Output is correct
3 Correct 557 ms 30456 KB Output is correct
4 Correct 576 ms 30840 KB Output is correct
5 Correct 551 ms 30456 KB Output is correct
6 Correct 558 ms 30456 KB Output is correct
7 Correct 557 ms 30456 KB Output is correct
8 Correct 538 ms 30968 KB Output is correct

Subtask #5
16.0 / 16.0

# 결과 실행 시간 메모리 Grader output
1 Correct 465 ms 27744 KB Output is correct
2 Correct 200 ms 36092 KB Output is correct
3 Correct 280 ms 35128 KB Output is correct
4 Correct 268 ms 35064 KB Output is correct
5 Correct 265 ms 34936 KB Output is correct
6 Correct 273 ms 35052 KB Output is correct
7 Correct 263 ms 35192 KB Output is correct
8 Correct 267 ms 35192 KB Output is correct
9 Correct 276 ms 35100 KB Output is correct
10 Correct 271 ms 35324 KB Output is correct
11 Correct 271 ms 35192 KB Output is correct
12 Correct 491 ms 31872 KB Output is correct
13 Correct 262 ms 35064 KB Output is correct
14 Correct 145 ms 39928 KB Output is correct
15 Correct 145 ms 39928 KB Output is correct
16 Correct 463 ms 31812 KB Output is correct
17 Correct 443 ms 31212 KB Output is correct
18 Correct 459 ms 31600 KB Output is correct
19 Correct 211 ms 36088 KB Output is correct
20 Correct 201 ms 35996 KB Output is correct
21 Correct 199 ms 35960 KB Output is correct
22 Correct 200 ms 36088 KB Output is correct

Subtask #6
22.0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 465 ms 27744 KB Output is correct
2 Correct 200 ms 36092 KB Output is correct
3 Correct 280 ms 35128 KB Output is correct
4 Correct 268 ms 35064 KB Output is correct
5 Correct 265 ms 34936 KB Output is correct
6 Correct 273 ms 35052 KB Output is correct
7 Correct 263 ms 35192 KB Output is correct
8 Correct 267 ms 35192 KB Output is correct
9 Correct 276 ms 35100 KB Output is correct
10 Correct 271 ms 35324 KB Output is correct
11 Correct 271 ms 35192 KB Output is correct
12 Correct 491 ms 31872 KB Output is correct
13 Correct 262 ms 35064 KB Output is correct
14 Correct 145 ms 39928 KB Output is correct
15 Correct 145 ms 39928 KB Output is correct
16 Correct 463 ms 31812 KB Output is correct
17 Correct 443 ms 31212 KB Output is correct
18 Correct 459 ms 31600 KB Output is correct
19 Correct 211 ms 36088 KB Output is correct
20 Correct 201 ms 35996 KB Output is correct
21 Correct 199 ms 35960 KB Output is correct
22 Correct 200 ms 36088 KB Output is correct
23 Correct 527 ms 32988 KB Output is correct
24 Correct 257 ms 36096 KB Output is correct
25 Correct 261 ms 30200 KB Output is correct
26 Correct 263 ms 29560 KB Output is correct
27 Correct 253 ms 29688 KB Output is correct
28 Correct 275 ms 30584 KB Output is correct
29 Correct 264 ms 29816 KB Output is correct
30 Correct 256 ms 30072 KB Output is correct
31 Correct 259 ms 30072 KB Output is correct
32 Correct 250 ms 29688 KB Output is correct
33 Correct 257 ms 30328 KB Output is correct
34 Correct 503 ms 31944 KB Output is correct
35 Correct 261 ms 30072 KB Output is correct
36 Correct 168 ms 41140 KB Output is correct
37 Correct 172 ms 41908 KB Output is correct
38 Correct 515 ms 32812 KB Output is correct
39 Correct 511 ms 31672 KB Output is correct
40 Correct 525 ms 32960 KB Output is correct
41 Correct 251 ms 36088 KB Output is correct
42 Correct 253 ms 36088 KB Output is correct
43 Correct 256 ms 36092 KB Output is correct
44 Correct 252 ms 36088 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 -