题解 | #牛牛的三元组问题#
牛牛的三元组问题
https://www.nowcoder.com/practice/72c6d735fb1144a2ba162976a4510839
import java.util.*; public class Solution { /** * 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可 * * * @param nums int整型一维数组 * @return int整型二维数组 */ public int[][] findTriplets (int[] nums) { // write code here List<int[]> res = new ArrayList<>(); Arrays.sort(nums); int l = nums.length; int rem =nums[0]-1; for(int i=0;i<l-2;i++){ if(rem==nums[i]) continue; int t = -nums[i]; rem = nums[i]; int rem2 = nums[i]-1; for(int j=i+1;j+1<l;j++) { if(nums[j]==rem2)continue; rem2=nums[j]; int tar = t-nums[j]; int index = findNumb(nums,j+1,l-1,tar); if(index>0&&index<=l) { int[] e = new int[]{nums[i],nums[j],nums[index]}; res.add(e); } } } int[][] resA = new int[res.size()][3]; res.toArray(resA); return resA; } int findNumb(int[] arr,int s,int e,int t){ if(s>e) return -1; int r = (s+e)/2; if(t<arr[r])return findNumb(arr,s,r-1,t); else if(t>arr[r]) return findNumb(arr,r+1,e,t); else return r; } }