Merge pull request #1150 from akgmage/dev

update contributing.md

Author: akgmage

CONTRIBUTING.md

@@ -22,6 +22,93 @@ Contributions are always welcome!
 - Provide link for further reading (optional)
 - Send a Pull Request (PR) against main branch and mention issue number in the request
 
+# Example program
+
+```go
+/*
+	Write a function that takes in two non-empty arrays of integers, finds the pair of numbers (one from each array)
+	whose absolute difference is closest to zero, and returns an array containing these two numbers, with the number from
+	the first array in the first position.
+
+	Note that the absolute difference of two integers is the distance between them on the real number line.
+	For example, the absolute difference of -5 and 5 is 10, and the absolute difference of -5 and -4 is 1.
+
+  	You can assume that there will only be one pair of numbers with the smallest difference.
+
+	Sample Input Array1 = [-1, 5, 10, 20, 28, 3]
+	Sample Input Array2 = [26, 134, 135, 15, 17]
+
+	Sample Output = [28, 26]
+
+    Explanation :
+
+	This code implements the Smallest Difference problem which takes two arrays of integers as input and returns a pair of integers,
+	one from each array, with the smallest absolute difference between them.
+
+	The function first initializes two variables current and smallest to the maximum integer value. It then sorts both input arrays
+	in ascending order using the sort.Ints function from the sort package.
+
+	The function then iterates through both arrays using two pointers, idx1 and idx2, initialized to 0. Inside the loop, it compares
+	the elements at the current indices of the two arrays, first and second, and calculates the absolute difference between
+	them in the current variable.
+
+	If current is smaller than the smallest variable, it updates smallest to current and assigns the current pair of integers
+	to the result variable.
+
+	The function returns the result variable, which contains the pair of integers with the smallest absolute difference.
+
+	If there are identical integers in the two input arrays, the function will return them immediately, without any further comparisons.
+
+	O(nlog(n) + mlog(m)) time | O(1) space - where n is the length of the first input array and m is the length of the second input array
+*/
+
+package main
+
+import (
+	"math"
+	"sort"
+)
+
+// SmallestDifference takes two integer slices as input and returns a slice with two integers.
+// The two integers in the returned slice have the smallest absolute difference among all pairs
+// of integers from the two input slices.
+func SmallestDifference(array1, array2 []int) []int {
+	// Initialize variables for the smallest difference and the current difference being calculated
+	current, smallest := math.MaxInt32, math.MaxInt32
+	// Sort the input slices
+	sort.Ints(array1)
+	sort.Ints(array2)
+	// Initialize variables for the indices for the two slices
+	idx1, idx2 := 0, 0
+	// Initialize an empty slice for the result
+	result := []int{}
+	// Loop through the two slices until we reach the end of one of the slices
+	for idx1 < len(array1) && idx2 < len(array2) {
+		// Get the values at the current indices for the two slices
+		first, second := array1[idx1], array2[idx2]
+		// Calculate the current difference between the two values
+		if first < second {
+			current = second - first
+			idx1++
+		} else if second < first {
+			current = first - second
+			idx2++
+		} else {
+			// If the two values are equal, we can return the pair
+			return []int{first, second}
+		}
+		// Update the smallest difference and result slice if the current difference is smaller
+		if smallest > current {
+			smallest = current
+			result = []int{first, second}
+		}
+	}
+	// Return the pair with the smallest absolute difference
+	return result
+}
+
+```
+
 ## What if the problem you want to add is not present in the issue?
 
 - You can suggest an idea for this project under issues tab (add list of questions you think it is important, it will be assigned to you)