/* Given an array of ints, is it possible to choose a group of some of the * ints, beginning at the start index, such that the group sums to the given * target? However, with the additional constraint that all 6's must be * chosen. (No loops needed.) */ public boolean groupSum6(int start, int[] nums, int target) { if(start >= nums.length) return target == 0; if(nums[start] == 6) return groupSum6(start+1, nums, target - 6); if(groupSum6(start+1, nums, target - nums[start])) return true; if(groupSum6(start+1, nums, target)) return true; return false; }