20分TLE求助

我该怎样优化？

#include <bits/stdc++.h>

using namespace std;

struct planet
{
    int x, y;
}s[10000005];

int n, m, k, parent[10000005];
map<int, bool> mp;

int find(int v1)
{
    while (v1 != parent[v1])
    {
        v1 = parent[v1];
    }
    return v1;
}

void _union(int v1, int v2)
{
    int p1 = find(v1);
    int p2 = find(v2);
    if (p1 != p2)
    {
        parent[p1] = p2;
    }
}

bool isSame(int v1, int v2)
{
    return find(v1) == find(v2);
}

int count_p()
{
    int sum = 0;
    for (int i = 0 ; i < n ; i ++)
    {
        if (parent[i] == i && mp[i])
        {
            sum ++;
        }
    }
    return sum;
}

void parent_i()
{
    for (int i = 0 ; i < n ; i ++)
    {
        parent[i] = i;
    }
}

int main()
{
    cin >> n >> m;
    for (int i = 0 ; i < n ; i ++)
    {
        mp[i] = true;
    }
    parent_i();
    for (int i = 1 ; i <= m ; i ++)
    {
        cin >> s[i].x >> s[i].y;
        _union(s[i].x, s[i].y);
    }
    cout << count_p() << endl;
    cin >> k;
    for (int i = 1 ; i <= k ; i ++)
    {
        parent_i();
        int p;
        cin >> p;
        mp[p] = false;
        for (int j = 1 ; j <= m ; j ++)
        {
            if (mp[s[j].x] && mp[s[j].y])
            {
                _union(s[j].x, s[j].y);
            }
        }
        cout << count_p() << endl;
    }
    return 0;
}