0015-3sum.go

functhreeSum(nums []int) [][]int {
n:=len(nums)

// Sort the given array
sort.Ints(nums)

varresult [][]int
fornum1Idx:=0; num1Idx<n-2; num1Idx++ {
// Skip all duplicates from left
// num1Idx>0 ensures this check is made only from 2nd element onwards
ifnum1Idx>0&&nums[num1Idx] ==nums[num1Idx-1] {
continue
 }

num2Idx:=num1Idx+1
num3Idx:=n-1
fornum2Idx<num3Idx {
sum:=nums[num2Idx] +nums[num3Idx] +nums[num1Idx]
ifsum==0 {
// Add triplet to result
result=append(result, []int{nums[num1Idx], nums[num2Idx], nums[num3Idx]})

num3Idx--

// Skip all duplicates from right
fornum2Idx<num3Idx&&nums[num3Idx] ==nums[num3Idx+1] {
num3Idx--
 }
 } elseifsum>0 {
// Decrement num3Idx to reduce sum value
num3Idx--
 } else {
// Increment num2Idx to increase sum value
num2Idx++
 }
 }
 }
returnresult
}