leetcode15 3Sum

/**

<span style="color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;">Given an array </span><span style="box-sizing: border-box; color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;">S</span><span style="color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;"> of </span><span style="box-sizing: border-box; color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;">n</span><span style="color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;"> integers, are there elements </span><span style="box-sizing: border-box; color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;">a</span><span style="color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;">, </span><span style="box-sizing: border-box; color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;">b</span><span style="color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;">, </span><span style="box-sizing: border-box; color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;">c</span><span style="color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;"> in </span><span style="box-sizing: border-box; color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;">S</span><span style="color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;"> such that </span><span style="box-sizing: border-box; color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;">a</span><span style="color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;"> + </span><span style="box-sizing: border-box; color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;">b</span><span style="color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;"> + </span><span style="box-sizing: border-box; color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;">c</span><span style="color: rgb(51, 51, 51); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 30px;"> = 0? Find all unique triplets in the array which gives the sum of zero.</span>

*/

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class Solution {

public List<List<Integer>> threeSum(int[] nums) {
List<List<Integer>> numbers = new ArrayList<List<Integer>>();

Arrays.sort(nums);

int n = nums.length;
for(int i = 0;i<n;i++){
if(i>0 && nums[i]==nums[i-1]) {
continue;
}
int j = i+1, k = n-1;
while(j<k){
if(j>i+1 && nums[j]==nums[j-1]){
j++;
continue;
}
if(nums[j]+nums[k]+nums[i]==0 ){
List<Integer> number = new ArrayList<Integer>();
number.add(nums[i]);
number.add(nums[j]);
number.add(nums[k]);
numbers.add(number);
j++;
k--;
}else{
if(nums[j]+nums[k]+nums[i]>0){
k--;
}else{
j++;
}
}
}
}
return numbers;
}
/**
* @param args
*/
public static void main(String[] args) {
int[] nums = {-4,-2,1,-5,-4,-4,4,-2,0,4,0,-2,3,1,-5,0};
List<List<Integer>> numbers = new Solution().threeSum(nums);
for(int i = 0;i<numbers.size();i++){
for (int j = 0; j < numbers.get(i).size(); j++) {
System.out.print(numbers.get(i).get(j)+" ");
}
System.out.println();
}
}

}