In this HackerRank Gemstones problem you have Given a list of minerals embedded in each of the rocks, display the number of types of gemstones in the collection.

HackerRank Genstones problem solution


Problem solution in Python programming.

import fileinput

stones = []
gems = []

for line in fileinput.input():
    if fileinput.lineno() == 1:
        lengths = int(line)
    else:
        stones.append(line.strip())

#print(stones)
for x in range(0, len(stones[0])):
    if stones[0][x] not in gems:
        gems.append(stones[0][x])
        for y in range(0, lengths):
            if stones[0][x] not in stones[y]:
                #print(x)
                try :
                    gems.remove(stones[0][x])
                except ValueError:
                    continue

print(len(gems))


Problem solution in Java Programming.

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {
    
    static int gemStones(ArrayList<String> array)
    {
    	String firstString = array.get(0);
    	
    	// charset with all unique chars
    	HashSet<String> charSet = new HashSet<String>();
    	
    	for (String c : firstString.split(""))
    	{
    		charSet.add(c);
    	}
    	
    	int total = 0;
    	for (String c : charSet)
    	{
    		Boolean exists = true;
    		for (int i = 1 ; i < array.size() ; i++)
    		{
    			String thisLine = array.get(i);
    			if (!thisLine.contains(c))
    			{
    				exists = false;
    			}
    		}
    		
    		if (exists)
    			total++;
    	}
    	
    	return total;
    }

   
 public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        
        int count = in.nextInt();
        // escape the \n
        in.nextLine();
        ArrayList <String> arrayList = new ArrayList<String>(count);
        
        for (int i=0;i<count;i++)
        {
        	String line = in.nextLine();
        	arrayList.add(line);
        }
        
        in.close();
        
        int result = gemStones(arrayList);
        System.out.println(result);
        
   }
}


Problem solution in C++ programming.

#include <cmath>
#include <ctime>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cassert>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <string>
#include <vector>
#include <sstream>
#include <iostream>
#include <algorithm>

#define DB(x) cerr << x << " "
#define DBN(x) cerr << #x << "=" << x << endl
#define DBL cerr << endl
#define sz(c) ((int)(c).size())
#define pb push_back
#define mp make_pair
#define endl '\n'

typedef long long int64;

using namespace std;

int n;
int cnt[26];

int main() {
  while (scanf("%d", &n) == 1) {
    memset(cnt, 0, sizeof(cnt));
    for (int i = 0; i < n; ++i) {
      char s[110];
      scanf("%s", s);
      set<int> was;
      for (int i = 0; s[i] != 0; ++i)
        if (!was.count(s[i])) {
          ++cnt[s[i] - 'a'];
          was.insert(s[i]);
        }
    }
    int res = 0;
    for (int i = 0; i < 26; ++i)
      if (cnt[i] == n) ++res;
    printf("%d\n", res);
  }
  return 0;
}


Problem solution in C programming.

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>

#define NL ('z' - 'a' + 1)

int main(int argc, char *argv[])
{
    if (argc > 1)
        freopen(argv[1], "r", stdin);

    //Helpers for input/output
    int N;
    int total[NL] = {0};
    int part[NL];
    unsigned char elem[101];
    int result = 0;
   
    scanf("%d\n", &N);
    for(int i=0; i<N; i++)
    {
        memset(part, 0, NL * sizeof(int));
        scanf("%s\n", elem);
        for (unsigned char *c = elem; *c; c++)
        {
            if (!part[*c - 'a'])
            {
                part[*c - 'a']++;
                total[*c - 'a']++;
            }
        }
    }
   
    for(int i=0; i<NL; i++)
    {
        if (total[i] == N)
            result++;
    }
    
    printf("%d\n", result);
    return 0;
}


Problem solution in JavaScript programming.

'use strict';

function processData(input) {
    var lines = input.split('\n').slice(1);
    var gemElements = lines.reduce(function(prev, curr, index, array) {
        var found = [];
        var letters = curr.split('').map(function(letter){
            if(prev.indexOf(letter) !== -1 && found.indexOf(letter) === -1) {
                found.push(letter);
                return letter; 
            }
        });
        return letters.join('');
    });
    console.log(gemElements.length);
}

process.stdin.resume();
process.stdin.setEncoding("ascii");
var _input = "";
process.stdin.on("data", function (input) { _input += input; });
process.stdin.on("end", function () { processData(_input); });