Pagini recente » Cod sursa (job #2669807) | Cod sursa (job #1851190) | Cod sursa (job #1236995) | Cod sursa (job #426291) | Cod sursa (job #2099881)
#include <fstream>
#include <vector>
using namespace std;
ifstream cin ("lca.in");
ofstream cout ("lca.out");
vector < vector < int > > gr(100100);
vector < int > dad (100100);
vector < int > lv (100100);
void dfs (int root){
lv[root] = lv[dad[root]] + 1;
for (auto &x : gr[root]){
dfs(x);
}
}
int main() {
ios::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
//BRUT
int n , m;
cin>>n>>m;
for (int i=2; i<=n; i++){
cin>>dad[i];
gr[dad[i]].push_back(i);
}
dfs(1);
for (int i=1; i<=m; i++){
int x , y;
cin>>x>>y;
while (x != y){
if (lv[x] > lv[y]){
x = dad[x];
}
else{
y = dad[y];
}
}
cout<<x<<'\n';
}
return 0;
}