Combination 조합 | 반복문

	int[] arr = {1, 2, 3, 4, 5};
	int len = arr.length;

	for(int i=0; i<len-2; i++) {
		for(int j=i+1; j<len-1; j++) {
			for(int k=j+1; k<len; k++) {
				System.out.println(arr[i] + ", " + arr[j] + ", " + arr[k]);
			}
		}
	}