#include "citymapping.h"
#include <bits/stdc++.h>
#define sz(x) (int)x.size()
#define all(x) x.begin(),x.end()
using namespace std ;
void find_roads(int N, int Q, int A[], int B[], int W[]) {
long long max_dist = 1000000000LL * N + 1LL ;
int rt = 2 ;
for(int i= 2 ; i <= N ; i++ ){
long long cur_dist = get_distance(i,1) ;
if(cur_dist > max_dist){
max_dist =cur_dist ;
rt = i ;
}
}
vector<int> prof(N+1 , 0 ) ;
for(int i = 1 ; i <= N ; i++ ){
if(i != rt ) prof[i] = get_distance(i,rt) ;
}
vector<int> vertices(N) ; iota(all(vertices) , 1 ) ;
sort(all(vertices) , [&](int a, int b){
return prof[a] < prof[b] ;
}) ;
vector<int> chainHead(N+1) ;
vector<int> chainTail(N+1) ;
vector<int> prox(N+1) ;
vector<int> sub(N+1) ;
vector<int> pai(N+1,-1) ;
vector<long long> diam(N+1) ;
vector< vector<int> > graph(N+1 , vector<int>()) ;
sub[rt] = 1 ;
function<void(int)> makeChains = [&](int x){
if(graph[x].empty()){
chainTail[x] = x ;
prox[x] = -1 ;
diam[x] = 0 ;
return ;
}
if(sz(graph[x]) > 1 && sub[graph[x][1]] > sub[graph[x][0]]){
swap(graph[x][0] , graph[x][1]) ;
}
prox[x] = graph[x][0] ;
chainHead[graph[x][0]] = chainHead[x] ;
makeChains(prox[x]) ;
chainTail[x] = chainTail[prox[x]] ;
diam[x] = diam[prox[x]]-prof[x]+prof[prox[x]] ;
if(sz(graph[x]) > 1 ){
chainHead[graph[x][1]] = graph[x][1] ;
makeChains(graph[x][1]) ;
}
} ;
int idAns = -1 ;
auto add = [&](int par, int son){
idAns++ ;
A[idAns] = par ;
B[idAns] = son ;
W[idAns] = prof[son]-prof[par];
pai[son] = par ;
graph[par].push_back(son) ;
while(son != -1){
sub[son]++ ;
son = pai[son] ;
}
} ;
for(int i = 1 , cur ; i < N ; i++ ){
cur = vertices[i] ;
chainHead[rt] = rt ;
makeChains(rt) ;
int p = rt ;
while(true){
long long X = prof[cur]-prof[p] ;
long long Y = get_distance(cur, chainTail[p]) ;
long long filete = X+Y-diam[p] ; filete >>= 1LL ;
Y -= filete ;
p = chainTail[p] ;
while(diam[p] < Y) p = pai[p] ;
if( sz(graph[p]) <= 1 ){
add(p,cur) ;
break ;
}
else{
p = graph[p][1] ;
}
}
}
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
18 ms |
680 KB |
Correct: 3506 out of 500000 queries used. |
2 |
Incorrect |
10 ms |
472 KB |
Too many calls to get_distance(). |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
18 ms |
680 KB |
Correct: 3506 out of 500000 queries used. |
2 |
Incorrect |
10 ms |
472 KB |
Too many calls to get_distance(). |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
17 ms |
468 KB |
Correct: 3687 out of 12000 queries used. |
2 |
Correct |
18 ms |
572 KB |
Correct: 2991 out of 12000 queries used. |
3 |
Correct |
16 ms |
468 KB |
Correct: 3560 out of 12000 queries used. |
4 |
Correct |
15 ms |
572 KB |
Correct: 3704 out of 12000 queries used. |
5 |
Correct |
16 ms |
576 KB |
Correct: 3599 out of 12000 queries used. |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
17 ms |
468 KB |
Correct: 3687 out of 12000 queries used. |
2 |
Correct |
18 ms |
572 KB |
Correct: 2991 out of 12000 queries used. |
3 |
Correct |
16 ms |
468 KB |
Correct: 3560 out of 12000 queries used. |
4 |
Correct |
15 ms |
572 KB |
Correct: 3704 out of 12000 queries used. |
5 |
Correct |
16 ms |
576 KB |
Correct: 3599 out of 12000 queries used. |
6 |
Execution timed out |
2075 ms |
600 KB |
Time limit exceeded |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
18 ms |
680 KB |
Correct: 3506 out of 500000 queries used. |
2 |
Incorrect |
10 ms |
472 KB |
Too many calls to get_distance(). |
3 |
Halted |
0 ms |
0 KB |
- |