From 3bca72cfd2db603ee3146978129be629dd8b2123 Mon Sep 17 00:00:00 2001
From: Ujjwal <75884061+UG-SEP@users.noreply.github.com>
Date: Thu, 29 Apr 2021 03:54:09 +0530
Subject: [PATCH] enh: jump search in C and C++ (#275)

* added jump search in c and c++

* added jump search

* fix typo mistake
---
 algorithms/C/README.md                        |  4 +-
 algorithms/C/searching/Jump-search.c          | 83 +++++++++++++++++++
 .../CPlusPlus/Searching/jump-search.cpp       | 66 +++++++++++++--
 3 files changed, 144 insertions(+), 9 deletions(-)
 create mode 100644 algorithms/C/searching/Jump-search.c

diff --git a/algorithms/C/README.md b/algorithms/C/README.md
index efa287a9..2ea6a755 100644
--- a/algorithms/C/README.md
+++ b/algorithms/C/README.md
@@ -29,6 +29,4 @@
 
 ## Searching
 - [Binary Search](searching/Binary-search.c)
-
-  
-
+- [Jump Search](searching/Jump-search.c)
diff --git a/algorithms/C/searching/Jump-search.c b/algorithms/C/searching/Jump-search.c
new file mode 100644
index 00000000..92922a68
--- /dev/null
+++ b/algorithms/C/searching/Jump-search.c
@@ -0,0 +1,83 @@
+/*
+Program to search data in array using Jump Search
+Jump Search: It is a way to search data in array where it jump sqrt(n-1) and if data is less
+than current then it started searching it linearly
+*/
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+
+//Function to search data linearly
+int jump_search(int *arr,int n,int jump,int to_search)
+{
+    int start=0,end=jump;
+    //until n(size) is greater than end run the loop
+    while(end<n)
+    {
+        //if the data to search is greater than the end of arr then assign end to start and end+jump in end
+        if(arr[end]<to_search)
+        {
+            start=end;
+            end=end+jump;
+        }
+        // else means the data is less then or equal to the data to search
+        else
+        {
+           //search linearly until end is greater or equal to start
+            while(start<=end)
+            {
+                //if the data is found then return that data index else add 1 in start and repeat the loop
+                if(arr[start]==to_search)
+                    return start;
+                    start++;
+            }
+        }
+    }
+    //if data not found then return -1 will tells that data didn't exist
+return -1;
+}
+//driver code
+int main()
+{
+    int n,*arr,jump,i,to_search,res;
+    printf("Enter size: ");
+    //taking the size of array
+    scanf("%d",&n);
+    //dynamically allocating memory and returning the base address and assign it to arr
+    arr=(int*)malloc(sizeof(int)*n);
+    for(i=0;i<n;i++)
+    {
+        scanf("%d",&arr[i]);
+    }
+    //find the number of jumps to take every time
+    jump=(int)sqrt(n-1);
+    printf("Enter the number to search: ");
+    //taking the data to search
+    scanf("%d",&to_search);
+    //calling jump function
+    res=jump_search(arr,n,jump,to_search);
+    // if res is equal to -1 that means data didn't exist
+    if(res==-1)
+        printf("Data Not Found \n");
+    else
+        printf("Data Found at index: %d",res);
+return 0;
+
+}
+/*
+Case 1:
+Input: Enter size: 10
+       1,2,3,4,5,6,7,8,9,10
+       Enter the data to search: 11
+Output: Data not Found
+
+Case 2:
+
+Input: Enter size: 10
+       1,2,3,4,5,6,7,8,9,10
+       Enter the data to search: 7
+Output: Data Found at index: 6
+
+Time complexity: O(squareroot (n))
+
+*/
diff --git a/algorithms/CPlusPlus/Searching/jump-search.cpp b/algorithms/CPlusPlus/Searching/jump-search.cpp
index cc452ce3..7fe16d5c 100644
--- a/algorithms/CPlusPlus/Searching/jump-search.cpp
+++ b/algorithms/CPlusPlus/Searching/jump-search.cpp
@@ -1,3 +1,5 @@
+// Function to search data using jump search
+
 #include <iostream>
 #include <cmath>
 using namespace std;
@@ -14,26 +16,78 @@ int jumpSearch(int arr[], int n, int key)
             end = n;            //if right exceeds then bound the range
     }
     for (int pos = start; pos < end; pos++)
-    { //perform linear search 
+    { //perform linear search
         if (arr[pos] == key)
             return pos;         //the correct position of the key
     }
     return -1;                  // if element is not found
 }
-
+//recursive jump search function to search data in an array
+int recursive_jump_search(int *arr,int start,int end,int n,int to_search,int jump)
+{
+    // if end index of n is greater than n that means data not found so return -1
+    if(end>n)
+        return -1;
+    // is the element to search is greater than end index and end index is less than n than we need to jump
+    else if(arr[end]<to_search)
+    {
+    start=end;
+    end=end+jump;
+    }
+    // if else block run means data is between start and end index so then search linearly
+    else
+    {
+                  // until start is less or equal to end run the loop
+                  while(start<=end)
+            {
+                // if data found then return the data index number
+                if(arr[start]==to_search)
+                    return start;
+               // if data not found at arr start th index then move forward
+                start++;
+            }
+            // if data not found the the loop will stop and return -1
+            return -1;
+    }
+// call the recursive jump search again with few changes in start and end
+return recursive_jump_search(arr,start,end,n,to_search,jump);
+}
 int main()
 {
     int n, key, loct;
-    cout << "Enter the length of arr:\n";
+    cout << "Enter the length of array: ";
     cin >> n;
     int arr[n];
-    cout << "Enter the elements of arr:\n";
+    cout << "Enter the elements of array:"<<endl;
     for (int i = 0; i < n; i++)
         cin >> arr[i]; // Taking input
     cout << "Enter search key: ";
     cin >> key;
-    if ((loct = jumpSearch(arr, n, key)) != -1)             //Calling of jumpSearch function and getting a location back
+    //Calling of jumpSearch function and getting a location back
+    cout<<"Iterative Solution:"<<endl;
+    if ((loct = jumpSearch(arr, n, key)) != -1)
         cout << "Element found at location: " << loct << endl;
     else
         cout << "Element does not exist in the array." << endl;
-}
\ No newline at end of file
+        cout<<"Recursive solution:"<<endl;
+        if ((loct=recursive_jump_search(arr,0,n-1,n,key,(int)sqrt(n-1))) != -1)             //Calling of recursive jump Search function and getting a location back
+        cout << "Element found at location: " << loct << endl;
+    else
+        cout << "Element does not exist in the array." << endl;
+
+return 0;
+
+}
+/*
+Input: Enter the length of array: 5
+       Enter the elements of array:
+       1 2  3  4  5
+       Enter search key: 4
+       Iterative Solution:
+       Element found at location: 3
+       Recursive Solution:
+       Element found at location: 3
+
+Time complexity: O(square root (n))
+
+*/