static List<List<Integer>> threeSum(int nums[]){

List<List<Integer>> list= new ArrayList<>();

int n= nums.length;

if(n < 3) return list;

Arrays.sort(nums);

for(int i=0; i< n-2; i++){

if(nums[i] > 0) break; // If the starting val is more then 0 then three sum will not be zero

if(nums[i] + nums[i+1] + nums[i+1] > 0) break;

if(nums[i] + nums[n-1] + nums[n-2] < 0) continue;

if(i > 0 && nums[i] == nums[i-1]) continue;

int low= i+1, high = n-1;

while(low < high){

int sum = nums[i] + nums[low] + nums[high];

if(sum == 0){

list.add(Arrays.asList(nums[i], nums[low], nums[high]));

while(low < high && nums[low] == nums[low + 1]) low++;

while(low < high && nums[high] == nums[high -1]) high--;

low++;

high--;

}

else if(sum < 0) low++;

else high--;

}

}

return list;

}

public static void main(String[] args) {

int nums[]={-1,0,1,2,-1,-4};

/*

System.out.println(threeSum(nums));

}

}