Given an array nums of n integers, are there elements a, b, c in nums such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero.
Note:
The solution set must not contain duplicate triplets.
Example:
Given array nums = [-1, 0, 1, 2, -1, -4],
A solution set is:
[
[-1, 0, 1],
[-1, -1, 2]
]
Solution:
class Solution {
public:
vector<vector<int>> threeSum(vector<int>& nums) {
vector<vector<int>> res;
int n = nums.size();
sort(nums.begin(), nums.end());
for(int i = 0; i<n-2; i++){
if(i > 0 && nums[i] == nums[i-1])
continue;
int target = 0 - nums[i], left = i+1, right = n-1;
while(left < right){
if(nums[left] + nums[right] == target){
res.push_back({nums[i], nums[left], nums[right]});
while(left < right && nums[left+1] == nums[left]) left++;
while(left < right && nums[right] == nums[right-1]) right--;
left++; right--;
}
else if(nums[left] + nums[right] < target)
left++;
else right--;
}
}
return res;
}
};
注意语法
res.push_back({nums[i], nums[left], nums[right]});
