feat: add jump search with O(sqrt(n)) and unit tests

searching/jump_search.c

@@ -1,85 +1,73 @@
 /**
- * @file jump_search.c
- * @brief Implementation of [jump
- * search](https://en.wikipedia.org/wiki/Jump_search) algorithm.
+ * Jump search implementation 
+ * author: George-Anastasios Koutsovasilis
+ * github: https://github.com/koutsovasilis-tech
+ * @param arr The sorted array 
+ * @param size The size of the sorted array 
+ * @param x The element we are trying to find 
  */
-#include <assert.h>
-#include <math.h>
+
 #include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <assert.h>
 
-/**
- * @brief Macro to return the minimum of two values
- */
-#define min(X, Y) ((X) < (Y) ? (X) : (Y))
 
-/**
- * @brief Implement Jump-search algorithm
- *
- * @param [in] arr Array to search within
- * @param x value to search for
- * @param n length of array
- * @return index where the value was found
- * @return -1 if value not found
- */
-int jump_search(const int *arr, int x, size_t n)
+int jump_search(int arr[], size_t size, int x)
 {
-    int step = floor(sqrt(n));
-    int prev = 0;
-
-    while (arr[min(step, n) - 1] < x)
+    if (size == 0) return -1;
+    size_t step = sqrt(size);
+    size_t prev = 0;
+    size_t i = 0;
+    while (i < size && arr[i] < x) // jumps till it finds the correct block or it exceeds it 
     {
-        prev = step;
-        step += floor(sqrt(n));
-        if (prev >= n)
+        prev = i;
+        i += step;
+        if (prev >= size)
         {
             return -1;
         }
     }
-
-    while (arr[prev] < x)
+    size_t limit = (i < size) ? i : size - 1; // limit because i might be larger than size 
+    for (size_t m = prev; m <= limit; m++) // linear search 
     {
-        prev = prev + 1;
-        if (prev == min(step, n))
+        if (arr[m] == x)
         {
-            return -1;
+            return m; 
         }
     }
-    if (arr[prev] == x)
-    {
-        return prev;
-    }
-    return -1;
+    return -1; 
 }
-
-/**
- * @brief Test implementation of the function
- *
- */
-void test()
+int main() 
 {
+    // Already sorted array for the tests 
     int arr[] = {0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610};
-    size_t n = sizeof(arr) / sizeof(int);
+    int size = sizeof(arr) / sizeof(arr[0]);
 
-    int x = 55;
-    printf("Test 1.... ");
-    int index = jump_search(arr, x, n);
-    assert(index == 10);
-    printf("passed\nTest 2.... ");
-    x = 56;
-    index = jump_search(arr, x, n);
-    assert(index == -1);
-    printf("passed\nTest 3.... ");
-    x = 13;
-    index = jump_search(arr, x, n);
-    assert(index == 7);
-    printf("passed\n");
-}
+    // Test Case 1: Element in the middle
+    int target1 = 55;
+    int result1 = jump_search(arr, size, target1);
+    assert(arr[result1] == target1);
+    printf("Test 1 Passed: Found %d at index %d\n", target1, result1);
 
-/**
- * @brief Main function
- */
-int main()
-{
-    test();
+    // Test Case 2: Element at the start 
+    int target2 = 0;
+    int result2 = jump_search(arr, size, target2);
+    assert(result2 == 0);
+    printf("Test 2 Passed: Found %d at index %d\n", target2, result2);
+
+    // Test Case 3: Element at the end 
+    int target3 = 610;
+    int result3 = jump_search(arr, size, target3);
+    assert(result3 == size - 1);
+    printf("Test 3 Passed: Found %d at index %d\n", target3, result3);
+
+    // Test Case 4: Element does not exist
+    int target4 = 100;
+    int result4 = jump_search(arr, size, target4);
+    assert(result4 == -1);
+    printf("Test 4 Passed: Element %d correctly not found\n", target4);
+    printf("\n--- ALL TESTS PASSED SUCCESSFULLY ---\n");
     return 0;
 }
+