four sum 4sum

class Solution:
    def fourSum(self, nums: List[int], tar: int) -> List[List[int]]:
        n=len(nums)
        nums.sort()
        ans=[]
        for i in range(n):
            #skip repeatitive vals
            if i>0 and nums[i]==nums[i-1]:continue
            for j in range(i+1,n):
                #skip repeatitive vals
                if j>i+1 and nums[j]==nums[j-1]:continue
                rsum=tar-nums[i]-nums[j]
                l,r=j+1,n-1
                while l<r:
                    find=nums[l]+nums[r]
                    if find<rsum:l+=1
                    elif find>rsum:r-=1
                    else:
                        ans.append([nums[i],nums[j],nums[l],nums[r]])
                        l,r=l+1,r-1
                        #skip repeatitive vals
                        while l<r and nums[l]==nums[l-1]:
                            l+=1
                        while l<r and nums[r]==nums[r+1]:
                            r-=1
        return ans