내 풀이

import java.util.Arrays;
class Solution {
    public int solution(int[] array) {
        int answer = 0;
        for( int i = 0 ; i < array.length ; i++){
            for(char ch :(""+ array[i]).toCharArray()){
                if(ch =='7'){
                    answer++;
                }
            }
        }
        return answer;
    }
}