LeetCode 01 Two Sum swift

class TwoSum {
    func sumTow(nums: [Int], target: Int)->[Int]{

        var ret:[Int]=[,];

        for (var x=;x<nums.count;x++){
            for(var y=x+;y<nums.count;y++){
                if(target==nums[x]+nums[y]){
                    ret[]=x+
                    ret[]=y+
                }
            }
        }
        return ret;
    }
}