graph connectivity

/****************************************************************************************
   *  Md. Abdulla Al Mamun (Nayon)
   *  ID: 1306001
   *  Session: 2013-2014
   *  Department of Computer Science and Engineering
   *  Begum Rokeya University, Rangpur (BRUR)
   *
   *  Project Name:         Graph Connectivity
   *  File Created on:      Monday, 2015-07-06-00.50.13
   *  Current File:         D:\My Codes\C and C++\Code-Blocks Projects\Graph Connectivity\main.cpp
   *  Language:             English (U.S.)
   *  Encoding:             windows-1252
*****************************************************************************************/
#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
#include <algorithm>
#include <vector>
#include <cmath>

using namespace std;

struct graph{
    int parent;
    int depth;
};

graph nodes[30];

void ini(int n)
{
    int i;
    for(i = 1; i <= n; i++){
        nodes[i].parent = i;
        nodes[i].depth = 0;
    }
}

int find_repre(int n)
{
    if(nodes[n].parent != n){
        nodes[n].parent = find_repre(nodes[n].parent);
    }
    return nodes[n].parent;
}

void make_friend(int a, int b)
{
    int x = find_repre(a);
    int y = find_repre(b);
    if(x != y){
        if(nodes[x].depth < nodes[y].depth)nodes[x].parent = y;
        else if(nodes[x].depth > nodes[y].depth)nodes[y].parent = x;
        else{
            nodes[y].parent = x;
            nodes[x].depth++;
        }
    }
}

int main()
{
    //freopen("in.txt", "r", stdin);
    int t, i, ans, n;
    char str[5], s, e;

    scanf("%d", &t);
    getchar();
    getchar();
    bool f = false;
    while(t--){
        if(f)printf("\n");
        f = true;
        gets(str);
        n = str[0] - 'A'+1;
        ini(n);
        while((gets(str)) && (strlen(str) != 0)){
            s = str[0];
            e = str[1];
            make_friend(s-'A'+1, e-'A'+1);
        }
        ans = 0;
        for(i = 1; i <= n; i++){
            if(nodes[i].parent == i)ans++;
        }
        printf("%d\n", ans);
    }
    return 0;
}