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답안 #301936

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
301936 2020-09-18T10:05:47 Z Nodir_Bobiev Aesthetic (NOI20_aesthetic) C++17
60 / 100
 596 ms 37436 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 540 ms 30584 KB Output is correct
2 Correct 542 ms 30584 KB Output is correct
3 Correct 535 ms 30200 KB Output is correct
4 Correct 544 ms 30200 KB Output is correct
5 Correct 529 ms 30328 KB Output is correct
6 Correct 577 ms 30812 KB Output is correct
7 Correct 555 ms 30840 KB Output is correct
8 Correct 557 ms 30972 KB Output is correct

Subtask #4
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 584 ms 30844 KB Output is correct
2 Correct 584 ms 30456 KB Output is correct
3 Correct 575 ms 30456 KB Output is correct
4 Correct 596 ms 30928 KB Output is correct
5 Correct 549 ms 30444 KB Output is correct
6 Correct 555 ms 30488 KB Output is correct
7 Correct 561 ms 30488 KB Output is correct
8 Correct 550 ms 30680 KB Output is correct

Subtask #5
16.0 / 16.0

# 결과 실행 시간 메모리 Grader output
1 Correct 496 ms 27672 KB Output is correct
2 Correct 204 ms 31480 KB Output is correct
3 Correct 275 ms 31096 KB Output is correct
4 Correct 271 ms 31096 KB Output is correct
5 Correct 271 ms 31224 KB Output is correct
6 Correct 275 ms 31128 KB Output is correct
7 Correct 275 ms 31096 KB Output is correct
8 Correct 277 ms 31184 KB Output is correct
9 Correct 267 ms 31040 KB Output is correct
10 Correct 267 ms 31352 KB Output is correct
11 Correct 267 ms 31100 KB Output is correct
12 Correct 471 ms 27608 KB Output is correct
13 Correct 297 ms 31112 KB Output is correct
14 Correct 143 ms 35576 KB Output is correct
15 Correct 144 ms 35576 KB Output is correct
16 Correct 448 ms 27464 KB Output is correct
17 Correct 449 ms 27168 KB Output is correct
18 Correct 460 ms 27404 KB Output is correct
19 Correct 202 ms 31732 KB Output is correct
20 Correct 200 ms 31608 KB Output is correct
21 Correct 200 ms 31612 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 496 ms 27672 KB Output is correct
2 Correct 204 ms 31480 KB Output is correct
3 Correct 275 ms 31096 KB Output is correct
4 Correct 271 ms 31096 KB Output is correct
5 Correct 271 ms 31224 KB Output is correct
6 Correct 275 ms 31128 KB Output is correct
7 Correct 275 ms 31096 KB Output is correct
8 Correct 277 ms 31184 KB Output is correct
9 Correct 267 ms 31040 KB Output is correct
10 Correct 267 ms 31352 KB Output is correct
11 Correct 267 ms 31100 KB Output is correct
12 Correct 471 ms 27608 KB Output is correct
13 Correct 297 ms 31112 KB Output is correct
14 Correct 143 ms 35576 KB Output is correct
15 Correct 144 ms 35576 KB Output is correct
16 Correct 448 ms 27464 KB Output is correct
17 Correct 449 ms 27168 KB Output is correct
18 Correct 460 ms 27404 KB Output is correct
19 Correct 202 ms 31732 KB Output is correct
20 Correct 200 ms 31608 KB Output is correct
21 Correct 200 ms 31612 KB Output is correct
22 Correct 198 ms 31608 KB Output is correct
23 Correct 526 ms 28592 KB Output is correct
24 Correct 253 ms 31736 KB Output is correct
25 Correct 251 ms 26412 KB Output is correct
26 Correct 248 ms 25720 KB Output is correct
27 Correct 245 ms 25720 KB Output is correct
28 Correct 256 ms 26360 KB Output is correct
29 Correct 259 ms 25596 KB Output is correct
30 Correct 256 ms 25976 KB Output is correct
31 Correct 258 ms 26108 KB Output is correct
32 Correct 250 ms 25720 KB Output is correct
33 Correct 263 ms 26104 KB Output is correct
34 Correct 511 ms 27520 KB Output is correct
35 Correct 260 ms 26104 KB Output is correct
36 Correct 161 ms 37420 KB Output is correct
37 Correct 172 ms 37436 KB Output is correct
38 Correct 496 ms 28284 KB Output is correct
39 Correct 494 ms 27448 KB Output is correct
40 Correct 502 ms 28476 KB Output is correct
41 Correct 252 ms 31676 KB Output is correct
42 Correct 252 ms 31992 KB Output is correct
43 Correct 255 ms 31608 KB Output is correct
44 Correct 252 ms 31864 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 -