标签：重复 nbsp input 数字 arrays 实现 ber arraylist can
Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sums to target.
Each number in candidates may only be used once in the combination.
Note:
target) will be positive integers.Example 1:
Input: candidates =[10,1,2,7,6,1,5], target =8, A solution set is: [ [1, 7], [1, 2, 5], [2, 6], [1, 1, 6] ]Example 2:
Input: candidates = [2,5,2,1,2], target = 5, A solution set is: [ [1,2,2], [5] ]
组合总和II。跟版本一类似，唯一不同的地方在于input里面是有重复数字的。那么这个题就需要排序了，同时helper函数中需要skip掉重复的数字，其余思路跟39题没有任何区别。
时间O(2^n)
空间O(n)
Java实现
1 class Solution { 2 public List<List<Integer>> combinationSum2(int[] candidates, int target) { 3 List<List<Integer>> res = new ArrayList<>(); 4 if (candidates == null || candidates.length == 0) { 5 return res; 6 } 7 Arrays.sort(candidates); 8 helper(res, new ArrayList<>(), candidates, target, 0); 9 return res; 10 } 11 12 private void helper(List<List<Integer>> res, List<Integer> list, int[] candidates, int target, int start) { 13 if (target < 0) { 14 return; 15 } 16 if (target == 0) { 17 res.add(new ArrayList<>(list)); 18 return; 19 } 20 for (int i = start; i < candidates.length; i++) { 21 if (i != start && candidates[i] == candidates[i - 1]) { 22 continue; 23 } 24 list.add(candidates[i]); 25 helper(res, list, candidates, target - candidates[i], i + 1); 26 list.remove(list.size() - 1); 27 } 28 } 29 }
[LeetCode] 40. Combination Sum II
标签：重复 nbsp input 数字 arrays 实现 ber arraylist can
原文地址：https://www.cnblogs.com/cnoodle/p/12996797.html
