Cod sursa(job #2870741)

Utilizator MoldovanAndrei1Moldovan Andrei MoldovanAndrei1 Data 12 martie 2022 15:34:31
Problema Lowest Common Ancestor Scor 30
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.79 kb
#include<bits/stdc++.h>
using namespace std;
const int NMAX=10005;
vector<int>v[NMAX];
int p[NMAX],d[NMAX];
void dfs(int nod)
{
    for(auto it:v[nod])
    {
        if(!d[it])
        {
            d[it]=d[nod]+1;
            dfs(it);
        }
    }
}
int lca(int a,int b)
{
    if(a==b)return a;
    if(d[a]>d[b])swap(a,b);
    if(d[a]<d[b])return lca(a,p[b]);
    if(d[a]==d[b])return lca(p[a],p[b]);
}
int main()
{
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
    int m,n,k,a,b,i;
    cin>>n>>m;
    for(i=2;i<=n;i++)
        {
            cin>>p[i];
            v[i].push_back(p[i]);
            v[p[i]].push_back(i);
        }
    d[1]=1;
    dfs(1);
    for(i=1;i<=m;i++)
    {
        cin>>a>>b;
        cout<<lca(a,b)<<'\n';
    }
}