标签：and dup begin cto nta contain while size cat
Given an array nums of n integers and an integer target, are there elements a, b, c, and d in nums such that a + b + c + d = target? Find all unique quadruplets in the array which gives the sum of target.
Note:
The solution set must not contain duplicate quadruplets.
Example:
Given array nums = [1, 0, -1, 0, -2, 2], and target = 0. A solution set is: [ [-1, 0, 0, 1], [-2, -1, 1, 2], [-2, 0, 0, 2] ]
C++:
class Solution { public: vector<vector<int>> fourSum(vector<int>& nums,int target) { vector<vector<int> > result; if (nums.size() < 4) return result; sort(nums.begin(), nums.end()); for (int i = 0; i < nums.size() - 3; i++){ if (i>0 && nums[i] == nums[i - 1]) continue; for (int j = i + 1; j < nums.size() - 2; j++){ if (j >i + 1 && nums[j] == nums[j - 1]) continue; for (int k = j + 1, m=nums.size()-1; k < m;){ auto sum = nums[i] + nums[j] + nums[k] + nums[m]; if (sum == target){ result.push_back(vector<int>({ nums[i], nums[j], nums[k], nums[m] })); while (nums[++k] == nums[k - 1] && k < m); while (nums[--m] == nums[m + 1] && k < m); } else if (sum < target){ k++; } else m--; } } } return result; } };
标签：and dup begin cto nta contain while size cat
原文地址：https://www.cnblogs.com/duan-decode/p/9575571.html
