3Sum

class Solution:
    # @param {integer[]} nums
    # @return {integer[][]}
    def threeSum(self, nums):
        '''
        if len(nums)<3:
            return []
        result=[]
        for i in range(len(nums)):
            dic={}
            for j in range(i+1,len(nums)):
                for k in range(j+1,len(nums)):
                    dic[nums[j]+nums[j]]=[j,k]
            if -nums[i] in dic:
                if sorted([nums[i],nums[dic[-nums[i]][0]],nums[dic[-nums[i]][1]]]) not in result:
                    result.append(sorted([nums[i],nums[dic[-nums[i]][0]],nums[dic[-nums[i]][1]]]))
        return result
        '''
        if len(nums)<3:
            return []
        nums.sort()
        result=[]
        for i in range(len(nums)-2):
            j=i+1
            k=len(nums)-1
            while j<k:
                if nums[j]+nums[k]<-1*nums[i]:
                # cant doo nums[i]+nums[j]+nums[i]<0 !
                    j+=1
                elif nums[j]+nums[k]==-1*nums[i]:
                    result.append([nums[i],nums[j],nums[k]])
                    j,k=j+1,k-1
                else:
                    k-=1
        res=[]
        for item in result:
            if item not in res:
                res.append(item)
        return res