영상
개념
package 배열4_개념;
import java.util.Arrays;
import java.util.Random;
/*
# 중복숫자 금지 해결방법 3가지
[방법2] check배열 활용
*/
public class 배열4_개념04_중복숫자종류 {
public static void main(String[] args) {
Random ran = new Random();
int[] arr = new int[4];
boolean[] check = new boolean[4];
/*
2 2 3 2 3 1 0
i = 0, r = 2 check[2] == false true arr = [3, 0, 0, 0], check = [false, false, true, false]
i = 1, r = 2 check[2] == false false arr = [3, 0, 0, 0], check = [false, false, true, false]
i = 1, r = 3 check[3] == false true arr = [3, 4, 0, 0], check = [false, false, true, true]
i = 2, r = 2 check[2] == false false arr = [3, 4, 0, 0], check = [false, false, true, true]
i = 2, r = 3 check[3] == false false arr = [3, 4, 0, 0], check = [false, false, true, true]
i = 2, r = 1 check[1] == false true arr = [3, 4, 2, 0], check = [false, true, true, true]
i = 3, r = 0 check[0] == false true arr = [3, 4, 2, 1], check = [true, true, true, true]
*/
// while문 해결해보기!
for(int i=0; i<4; i++) {
int r = ran.nextInt(4);
System.out.println(r);
if(check[r] == false) {
check[r] = true;
arr[i] = r + 1;
}else {
i -= 1;
}
}
System.out.println(Arrays.toString(arr));
System.out.println(Arrays.toString(check));
}
}
Java
복사