459 - Graph Connectivity

Problem Link

#include<bits/stdc++.h>
using namespace std;

const int MAXN = 30;
int parent[MAXN];

void opt()
{
    for(int i = 1; i < MAXN; i++)
        parent[i] = i;
}

int find_parent(int x)
{
    if(parent[x]==x)
        return x;
    return parent[x] = find_parent(parent[x]);
}

void make_union(int x, int y)
{
    parent[find_parent(x)] = find_parent(y);
}

bool isUnion(int x, int y)
{
    return find_parent(x) == find_parent(y);
}

int main()
{
    int T, t;
    cin>>T;
    t = T;
    getchar();
    while(T--)
    {
        if(t-1!=T)
            cout<<endl;
        opt();
        int n;
        char ch;
        string s;
        cin>>ch;
        getchar();
        n = 1 + (ch - 'A');
        while(getline(cin,s) && s!="")
        {
            int a, b;
            a = 1 + (s[0] - 'A');
            b = 1 + (s[1] - 'A');
            if(!isUnion(a,b))
            {
                make_union(a,b);
                n--;
            }
        }
        cout<<n<<endl;
    }

    return 0;
}