average pair find program added

Author: sanjaydeveloper15

Multiple-Pointers/average-pair.js

@@ -0,0 +1,37 @@
+// Write a function called averagePair. Given a sorted array of integers and a target average,
+// determine if there is a pair of values in the array where the average of the pair equals the target average.
+// There may be more than one pair that matches the average target.
+
+function averagePair(inputSortedArray, pairAverage) {
+    // validations
+    if (!Array.isArray(inputSortedArray)) {
+        return 'Input parameter should be array only'
+    }
+    const arrCounts = inputSortedArray.length
+    let resultArr = []
+    if (arrCounts > 0) {
+        let leftIndex = 0, rightIndex = arrCounts - 1
+        while (leftIndex < rightIndex) {
+            // console.log(leftIndex, rightIndex)
+            const leftIndexVal = inputSortedArray[leftIndex]
+            const rightIndexVal = inputSortedArray[rightIndex]
+            const sum = (leftIndexVal + rightIndexVal)/2
+            if (sum === pairAverage) {
+                resultArr.push(leftIndexVal, rightIndexVal)
+                break
+            } else if (sum < pairAverage) {
+                leftIndex++
+            } else {
+                rightIndex--
+            }
+        }
+
+    }
+    console.log('---------------------------------------------')
+    return resultArr.length > 0 ? resultArr : undefined
+}
+
+console.log(averagePair([1, 2, 3], 2.5)); // true
+console.log(averagePair([1, 3, 3, 5, 6, 7, 10, 12, 19], 8)); // true
+console.log(averagePair([-1, 0, 3, 4, 5, 6], 4.1)); // false
+console.log(averagePair([], 4)); // false