【HackerRank】Gem Stones

Gem Stones

John has discovered various rocks. Each rock is composed of various elements, and each element is represented by a lowercase latin letter from 'a' to 'z'. An element can be present multiple times in a rock. An element is called a 'gem-element' if it occurs at least once in each of the rocks.

Given the list of rocks with their compositions, display the number of gem-elements that exist in those rocks.

Input Format
The first line consists of N, the number of rocks.
Each of the next N lines contain rocks' composition. Each composition consists of lowercase letters of English alphabet.

Output Format
Print the number gem-elements that exist in those rocks.

Constraints
1 ≤ N ≤ 100
Each composition consists of only small latin letters ('a'-'z').
1 ≤ Length of each composition ≤ 100

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题解：

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

 public class Solution {
    static int[] Gem_Stones(String[] ele){
        int[] answer = new int[27];
        for(int i = 0;i < ele.length;i++){
            boolean[] has = new boolean[27];
            for(int j =0;j < ele[i].length();j++){
                char temp = ele[i].charAt(j);
                if(!has[temp-'a']){
                    answer[temp-'a']++;
                    has[temp-'a'] = true;
                }
            }
        }
        return answer;
    }

  public static void main(String[] args) {
         Scanner in = new Scanner(System.in);
         int t;
         t = in.nextInt();
         String[] strings= new String[t];
         for(int i = 0;i < t;i++){
             strings[i] = in.next();
         }
         int[] answer = Gem_Stones(strings);
         int count = 0;
         for(int i = 0;i < answer.length;i++)
             if(answer[i]== t )
                 count++;
         System.out.print(count);
    }
 }