From 7fd12991f74280018724920d73761ef6328b51b8 Mon Sep 17 00:00:00 2001
From: Krishna Vedala <krishna.vedala@ieee.org>
Date: Thu, 28 May 2020 20:31:41 -0400
Subject: [PATCH]  document interpolation search

---
 search/interpolation_search.cpp | 89 +++++++++++++++++++++------------
 1 file changed, 57 insertions(+), 32 deletions(-)

diff --git a/search/interpolation_search.cpp b/search/interpolation_search.cpp
index afa9e7c50..e12dbd157 100644
--- a/search/interpolation_search.cpp
+++ b/search/interpolation_search.cpp
@@ -1,36 +1,61 @@
-#include<iostream>
+/**
+ * \file
+ * \brief [Interpolation
+ * search](https://en.wikipedia.org/wiki/Interpolation_search) algorithm
+ */
+#include <iostream>
 
-// function to search the value in an array using interpolation search
-int search(int arr[], int value, int len) {
-        int low = 0, high, mid;
-        high = len-1;
-        while (arr[low] <= value && arr[high] >= value) {
-            mid = (low + ((value-arr[low])*(high-low)) / (arr[high]-arr[low]));
-            if (arr[mid] > value)
-                     high = mid-1;
-            else if (arr[mid] < value)
-                     low = mid+1;
-            else
-                     return mid;
-            }
-        if (arr[low] == value)
-                return low;
-        return 0;
+/** function to search the value in an array using interpolation search
+ * \param [in] arr array to search in
+ * \param [in] value value to search for
+ * \param [in] len length of array
+ * \returns index where the value is found
+ * \returns 0 if not found
+ */
+int interpolation_search(int arr[], int value, int len) {
+    int low = 0, high, mid;
+    high = len - 1;
+
+    while (arr[low] <= value && arr[high] >= value) {
+        mid = (low +
+               ((value - arr[low]) * (high - low)) / (arr[high] - arr[low]));
+        if (arr[mid] > value)
+            high = mid - 1;
+        else if (arr[mid] < value)
+            low = mid + 1;
+        else
+            return mid;
+    }
+
+    if (arr[low] == value)
+        return low;
+
+    return 0;
 }
 
+/** main function */
 int main() {
-        int n, value, array[100], re;
-        std::cout << "Enter the size of array(less than 100) : ";
-        std::cin >> n;
-        std::cout << "array in ascending (increasing) order : " << std::endl;
-        for (int i=0; i < n; i++)
-                std::cin >> array[i];
-        std::cout << "Enter the value you want to search : ";
-        std::cin >> value;
-        re = search(array, value, n);
-        if (re == 0)
-                std::cout << "Entered value is not in the array" << std::endl;
-        else
-                std::cout << "The value is at the position " << re << std::endl;
-        return 0;
-        }
+    int n, value, re;
+
+    std::cout << "Enter the size of array(less than 100) : ";
+    std::cin >> n;
+
+    int *array = new int[n];
+
+    std::cout << "array in ascending (increasing) order : " << std::endl;
+
+    for (int i = 0; i < n; i++) std::cin >> array[i];
+
+    std::cout << "Enter the value you want to search : ";
+    std::cin >> value;
+
+    re = interpolation_search(array, value, n);
+
+    if (re == 0)
+        std::cout << "Entered value is not in the array" << std::endl;
+    else
+        std::cout << "The value is at the position " << re << std::endl;
+
+    delete[] array;
+    return 0;
+}