## Solución al problema número 1249B2 de Codeforces - 1249B2.

Cualquier duda no dudes en contactar.

``````#include <bits/stdc++.h>

using namespace std;

const int MAXN = 200100;
const int INF = 0x3f3f3f3f;

struct edge{
int from, to, weight;
edge(){}
edge(int a, int b, int c){
from = a;
to = b;
weight = c;
}
};

struct state{
int node, dist;
state(){}
state(int a, int b){
node = a; dist = b;
}
bool operator<(const state &other)const{ // sobrecarga de operadores para ordenar
return other.dist < dist;
}
};

vector<edge> graph[MAXN];
int dist[MAXN];
int check[MAXN];
int index=0;

int N,E;

int dijkstra(int start, int end){
dist[start] = 0;
priority_queue<state> pq;
pq.push(state(start, 0));
while(!pq.empty()){
state cur = pq.top(); pq.pop();
if(dist[cur.node] < cur.dist) continue;
if(cur.node == end) return cur.dist;
for(int i=0;i<graph[cur.node].size();i++){
int dest = graph[cur.node][i].to;
int wht = graph[cur.node][i].weight + cur.dist;
if(dist[dest] <= wht) continue;
dist[dest] = wht;
check[dest]=index;
check[cur.node]=index;
pq.push(state(dest, wht));
}
}
return -1;
}

int main(){
int n,m; scanf("%d",&n);
while(n--){
scanf("%d",&m);
N=E=m;
memset(dist,0x3f,sizeof(dist));
int arr[m+1];
for(int i=1;i<=N;i++) graph[i].clear(); // limpia el grafo
for(int i=1;i<=E;i++){
int to; scanf("%d",&to); arr[i]=to;
graph[i].push_back(edge(i,to,1));
}
memset(check,-1,sizeof(check));
vector<int> V;
index=-1;
memset(dist,0x3f,sizeof(dist));
for(int i=1; i<=m;i++) {
//memset(dist,0x3f,sizeof(dist));
int indexRes;
if(check[i]==-1) { index++; V.push_back(dijkstra(arr[i],i)+1); indexRes=index;  }
else indexRes=check[i];
if(i==1) printf("%d",V[indexRes]);
else printf(" %d",V[indexRes]);
}
printf("\n");
for(int i=1;i<=N;i++) graph[i].clear();
}
return 0;
}``````