标签：des style class blog c code
Given an array S of n integers, are there elements a, b, c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero.
Note:
For example, given array S = {-1 0 1 2 -1 -4},
A solution set is:
(-1, 0, 1)
(-1, -1, 2)
public class Solution { public ArrayList<ArrayList<Integer>> threeSum(int[] num) { ArrayList<ArrayList<Integer>> re = new ArrayList<ArrayList<Integer>>(); Map<ArrayList<Integer>,Integer> map = new HashMap<ArrayList<Integer>,Integer>(); ArrayList<Integer> ai = new ArrayList<Integer>(); if(num.length<=2) return re; Arrays.sort(num); for(int i=0;i<num.length-2;i++){ int temp = num[i]; ai = new ArrayList<Integer>(); ai.add(temp); int start = i+1; int end=num.length-1; int target = -temp; while(end>start){ if(num[start]+num[end]==target){ ai.add(num[start]); ai.add(num[end]); map.put(ai, 1); ai=new ArrayList<Integer>(); ai.add(temp); start++; end--; continue; } if(num[start]+num[end]>target){ end--; continue; } if(num[start]+num[end]<target){ start++; continue; } } } re.addAll(map.keySet()); return re; } }
标签：des style class blog c code
原文地址：http://www.cnblogs.com/yixianyixian/p/3742648.html
