# Given an array of ints, is it possible to choose a group of some # of the ints, such that the group sums to the given target? # This is a classic backtracking recursion problem. Once you # understand the recursive backtracking strategy in this problem, # you can use the same pattern for many problems to search a space # of choices. Rather than looking at the whole array, our convention # is to consider the part of the array starting at index start and # continuing to the end of the array. The caller can specify the # whole array simply by passing start as 0. No loops are needed -- # the recursive calls progress down the array. def groupSum(start, nums, target): # 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.) def groupSum6(start, nums, target): # Given an array of ints, is it possible to choose a group of some # of the ints, such that the group sums to the given target with this # additional constraint: If a value in the array is chosen to be in # the group, the value immediately following it in the array must # not be chosen. (No loops needed.) def groupNoAdj(start, nums, target): # Given an array of ints, is it possible to choose a group # of some of the ints, such that the group sums to the given # target with these additional constraints: all multiples of # 5 in the array must be included in the group. If the value # immediately following a multiple of 5 is 1, it must not # be chosen. (No loops needed.) def groupSum5(start, nums, target): # Given an array of ints, is it possible to choose a group of some # of the ints, such that the group sums to the given target? # This is a classic backtracking recursion problem. Once you # understand the recursive backtracking strategy in this problem, # you can use the same pattern for many problems to search a space # of choices. Rather than looking at the whole array, our convention # is to consider the part of the array starting at index start and # continuing to the end of the array. The caller can specify the # whole array simply by passing start as 0. No loops are needed -- # the recursive calls progress down the array. def groupSum(start, nums, target): # 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.) def groupSum6(start, nums, target): # Given an array of ints, is it possible to choose a group of some # of the ints, such that the group sums to the given target with this # additional constraint: If a value in the array is chosen to be in # the group, the value immediately following it in the array must # not be chosen. (No loops needed.) def groupNoAdj(start, nums, target): # Given an array of ints, is it possible to choose a group # of some of the ints, such that the group sums to the given # target with these additional constraints: all multiples of # 5 in the array must be included in the group. If the value # immediately following a multiple of 5 is 1, it must not # be chosen. (No loops needed.) def groupSum5(start, nums, target)