public class Main { private static int sum = 0; public static int[] scores = {2,2,2,2,2,2,2,2,2,2,4,4,4,4,4,4,4,4,4,4,8,8,8,8,8}; public static void main(String[] args) { for (int i = 0; i <= 100; i+=2) { sum = 0; backTracking(0, 0, 0, i); System.out.println(i + ": " + sum); } } public static void backTracking(int index, int score, int errNum, int target){ if (errNum >= 3) return; if (score == target) { sum++; return; } if (score > target) { return; } for (int i = index; i < 25; i++) { score += scores[i]; backTracking(i + 1, score,errNum,target); score -= scores[i]; errNum++; } } }