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Submission #260764

# Submission time Handle Problem Language Result Execution time Memory
260764 2020-08-10T21:09:56 Z test2 One-Way Streets (CEOI17_oneway) C++14
100 / 100
 175 ms 21364 KB 
#include<bits/stdc++.h>

#define I inline void

using namespace std ; 
using ll = long long ; 
using ld = long double ; 

const int N = 1e5 + 7 ; 

int n , m; 
string ans ; 
std::vector<pair<int , int > > adj[N];
int tim[N] ;
int t , tmr ; 
int fat[N] , par[N] , fate[N] , h[N] ; 
int st[N] , en[N] , a[N] , dir[N] ; 
int up[N][18] ; 

int cols[N] , col ; 

bool upper(int u , int v){
	return st[v] >= st[u] && en[v] <=en[u] ; 
}

int fin(int x){
	if(x == fat[x])return x ; 
	return fat[x] = fin(fat[x]) ; 
}

I link(int u , int v){
	int uu = fin(u) ; 
	int vv = fin(v) ; 
	if(uu != vv){
		fat[uu] = vv ;
	}
}

I rec(int u , int v , int mask){

	if(tim[u] < tim[v])swap(u , v) ; 
	u = fin(u) ; 
	while( h[v] < h[u]){
		if(!a[fate[u]]){
			if(mask  == 1){
				a[fate[u]] = (dir[fate[u]] == u ? 1 : 2 ) ; 
			}else if(mask == 2){
				a[fate[u]] = (dir[fate[u]] == u ? 2 : 1) ; 
			}
			else{
				a[fate[u]] = mask ;
			}
		}
		link(u , up[u][0]) ; 
		u = fin(u) ; 
	}
}



int lca(int u , int v){
	if(upper(u , v))return u ; 
	if(upper(v , u))return v ;
	for(int i = 17 ; i>= 0 ;i--){
		if(!upper(up[u][i] , v)){
			u = up[u][i];
		}
	}
	return up[u][0] ; 
}

I dfs(int x , int p ){

	tim[x] = ++ t;
	st[x] = ++ tmr ;
	up[x][0] = p ; 
	h[x] = h[p]  + 1 ; 

	for(int i = 1;i < 18 ;i++){
		up[x][i] = up[up[x][i-1]][i-1] ; 
	}
	for(auto u : adj[x]){
		if(u.first == p)continue ; 
		if(tim[u.first]){
			int l = lca(u.first , x) ; 
			rec(x , u.first , 3) ;
			a[u.second] =  3;

		}else{
			fate[u.first] = u.second ; 
			dfs(u.first , x) ;
		}
	}
	en[x] = ++ tmr ;
}


I pre(){
	for(int i = 0 ; i < N ;i++)
		fat[i] = i ; 
}


int main(){
	ios_base::sync_with_stdio(0) ; 
	cin.tie(0) ; 
	//freopen("in.in" , "r" , stdin) ; 
	pre() ; 
	cin >> n >> m ; 
	for(int i = 0 ;i < m ;i++){
		int u , v; 
		cin >> u >> v ; 
		dir[i] = v ; 
		if(u == v){
			a[i] = 3 ;
			continue ;
		}
		adj[u].push_back({v , i}) ; 
		adj[v].push_back({u , i }) ; 
	}
	for(int i = 1; i<=n;i++)
		if(!tim[i])
			dfs(i, i ) ; 

		int k ; cin >> k ;
		for(int i = 0 ;i < k ;i++){
			int u , v ;
			cin >> u >> v; 
			if(u == v)continue ; 
			int lc = lca(u , v) ;

			rec(u , lc , 1) ; 
			rec(v , lc , 2) ; 
		}

		for(int i = 0 ;i < m;i++){
			if(a[i] == 3)ans+='B' ; 
			else if(a[i] == 2)ans+='R' ;
			else if(a[i] == 1) ans+='L' ;
			else ans+='B' ;
		}

		cout<< ans ;

		return 0 ;
	}

Compilation message

oneway.cpp: In function 'void dfs(int, int)':
oneway.cpp:85:8: warning: unused variable 'l' [-Wunused-variable]
    int l = lca(u.first , x) ; 
        ^
oneway.cpp: In function 'int main()':
oneway.cpp:121:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(int i = 1; i<=n;i++)
  ^~~
oneway.cpp:125:3: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   int k ; cin >> k ;
   ^~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3072 KB Output is correct
2 Correct 2 ms 3072 KB Output is correct
3 Correct 2 ms 3200 KB Output is correct
4 Correct 3 ms 3200 KB Output is correct
5 Correct 2 ms 3328 KB Output is correct
6 Correct 3 ms 3200 KB Output is correct
7 Correct 3 ms 3328 KB Output is correct
8 Correct 3 ms 3200 KB Output is correct
9 Correct 2 ms 3200 KB Output is correct
10 Correct 2 ms 3200 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3072 KB Output is correct
2 Correct 2 ms 3072 KB Output is correct
3 Correct 2 ms 3200 KB Output is correct
4 Correct 3 ms 3200 KB Output is correct
5 Correct 2 ms 3328 KB Output is correct
6 Correct 3 ms 3200 KB Output is correct
7 Correct 3 ms 3328 KB Output is correct
8 Correct 3 ms 3200 KB Output is correct
9 Correct 2 ms 3200 KB Output is correct
10 Correct 2 ms 3200 KB Output is correct
11 Correct 47 ms 9208 KB Output is correct
12 Correct 62 ms 11768 KB Output is correct
13 Correct 75 ms 14200 KB Output is correct
14 Correct 101 ms 17152 KB Output is correct
15 Correct 112 ms 18040 KB Output is correct
16 Correct 94 ms 17784 KB Output is correct
17 Correct 97 ms 18808 KB Output is correct
18 Correct 94 ms 18040 KB Output is correct
19 Correct 103 ms 19516 KB Output is correct
20 Correct 74 ms 13236 KB Output is correct
21 Correct 70 ms 13280 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3072 KB Output is correct
2 Correct 2 ms 3072 KB Output is correct
3 Correct 2 ms 3200 KB Output is correct
4 Correct 3 ms 3200 KB Output is correct
5 Correct 2 ms 3328 KB Output is correct
6 Correct 3 ms 3200 KB Output is correct
7 Correct 3 ms 3328 KB Output is correct
8 Correct 3 ms 3200 KB Output is correct
9 Correct 2 ms 3200 KB Output is correct
10 Correct 2 ms 3200 KB Output is correct
11 Correct 47 ms 9208 KB Output is correct
12 Correct 62 ms 11768 KB Output is correct
13 Correct 75 ms 14200 KB Output is correct
14 Correct 101 ms 17152 KB Output is correct
15 Correct 112 ms 18040 KB Output is correct
16 Correct 94 ms 17784 KB Output is correct
17 Correct 97 ms 18808 KB Output is correct
18 Correct 94 ms 18040 KB Output is correct
19 Correct 103 ms 19516 KB Output is correct
20 Correct 74 ms 13236 KB Output is correct
21 Correct 70 ms 13280 KB Output is correct
22 Correct 175 ms 19960 KB Output is correct
23 Correct 173 ms 19252 KB Output is correct
24 Correct 159 ms 19216 KB Output is correct
25 Correct 166 ms 21364 KB Output is correct
26 Correct 168 ms 19704 KB Output is correct
27 Correct 159 ms 19296 KB Output is correct
28 Correct 41 ms 7544 KB Output is correct
29 Correct 115 ms 14188 KB Output is correct
30 Correct 113 ms 14200 KB Output is correct
31 Correct 117 ms 14456 KB Output is correct
32 Correct 124 ms 16504 KB Output is correct