1. 문제
2. 풀이
import java.util.Arrays;
class Solution {
public int solution(int[] array) {
int answer = 0;
String str = Arrays.stream(array)
.mapToObj(String::valueOf)
.reduce((x, y) -> x + ", " + y)
.get();
String[] strArr = str.split("");
for(int i = 0; i < strArr.length; i++) {
if(strArr[i].equals("7")) {
answer++;
}
}
return answer;
}
}