Company Queries II

input/code.cpp: In function 'void solve()':
input/code.cpp:59:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |         for (int a = 0; a < parents[i].size(); a++)
      |                         ~~^~~~~~~~~~~~~~~~~~~

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <numeric>
#include <unordered_map>
#include <queue>
#include <climits>
#include <cmath>
 
//#define int long long
using namespace std;
 
vector<int> deepness;
vector<vector<int>> adj;
vector<vector<int>> parents;
 
void calc(int i, int deep)
{
    deepness[i] = deep;
    for (auto& num : adj[i])
    {
        calc(num, deep + 1);
    }
}
int getParent(int a, int i)
{
    int loopIdx = 0;
    while (i > 0)
    {
        if ((i & 1) == 1)
            a = parents[loopIdx][a];
        loopIdx++;
        i >>= 1;
    }
    return a;
}
 
void solve()
{
    int n, q;
    cin >> n >> q;
    
    adj = vector<vector<int>>(n, vector<int>());
    parents = vector<vector<int>>(35, vector<int>(n));
    deepness = vector<int>(n);
    parents[0][0] = 0;
    for (int i = 1; i < n; i++)
    {
        int a;
        cin >> a;
        a--;
        adj[a].push_back(i);
        parents[0][i] = a;
    }
 
    for (int i = 1; i < 35; i++)
    {
        for (int a = 0; a < parents[i].size(); a++)
            parents[i][a] = parents[i-1][parents[i-1][a]];
    }
    calc(0, 0);
 
    for (int i = 0; i < q; i++)
    {
        int a, b;
        cin >> a >> b;
        a--; b--;
 
        if (deepness[a] > deepness[b])
            a = getParent(a, deepness[a] - deepness[b]);
        else
            b = getParent(b, deepness[b] - deepness[a]);
        
        if (a != b)
        {
            for (int i = parents.size() - 1; i >= 0; i--)
            {
                if (parents[i][a] != parents[i][b])
                {
                    a = parents[i][a];
                    b = parents[i][b];
                }
            }
            a = parents[0][a];
        }
 
        cout << a+1 << '\n';
    }
 
 
}
 
signed main()
{
    //ios::sync_with_stdio(0);
    //cin.tie(0);
 
    int t = 1;
 
    //cin >> t;
 
    for (int i = 0; i < t; i++)
        solve();
 
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED