Write a Golang program to find pairs with the given sum in an array(O(n))

Examples

Input Array = [1, 3, 5, 7, 8, 9], sum = 11 => (3, 8)

Approach to solve this problem

Step 1: Define a method that accepts an array and sum.

Step 2: Define a mapping variable, type map[int]int.

Step 3: Iterate the given array as i.

Step 4: If key in mapping sum-arr[i] is not present, then mapping[arr[i]]=i.

Step 5: If present, then print “pair is found”.

Step 6: At the end, print that “pair not found”.

Program

package main
import "fmt"
func findSumPair(arr []int, sum int){
   mapping := make(map[int]int)
   for i:=0; i<len(arr); i++{
      if mapping[sum-arr[i]] == 0{
         mapping[arr[i]] = i
      } else {
         fmt.Printf("Pair for given sum is (%d, %d).\n", arr[mapping[sum-arr[i]]], arr[i])
         return
      }
   }
   fmt.Println("Pair not found in given array.")
}

func main(){
   findSumPair([]int{4, 3, 6, 7, 8, 1, 9}, 15)
   findSumPair([]int{4, 3, 6, 7, 8, 1, 9}, 100)
}

Output

Pair for given sum is (7, 8).
Pair not found in given array.