Given an integer array with all positive numbers and no duplicates, find the number of possible combinations that add up to a positive integer target.
Example:
nums = [1, 2, 3] target = 4 The possible combination ways are: (1, 1, 1, 1) (1, 1, 2) (1, 2, 1) (1, 3) (2, 1, 1) (2, 2) (3, 1) Note that different sequences are counted as different combinations. Therefore the output is 7.
Follow up:What if negative numbers are allowed in the given array?How does it change the problem?What limitation we need to add to the question to allow negative numbers?
转载于:https://www.cnblogs.com/liuliu5151/p/10873323.html
