Done

binary_search.c

@@ -3,7 +3,7 @@
  *-----------------------------------------------------------------------------
  * Exercise Number: S07
  * Title:			Binary search implementation
- * Author:			*/<your name>;/*
+ * Author:			Marc Tismonar
  *-----------------------------------------------------------------------------
  * Description:
  * Implements the binary search algorithm
@@ -11,3 +11,91 @@
 */
 
 #include "binary_search.h"
+
+/**
+ * Searches the given needle within the given haystack using binary search approach.
+ * 
+ * Implementation hint: delegate the invocation to function `binary_search_list_limited(…)`.
+ * 
+ * @param haystack The sorted list in which the `needle` is searched.
+ * @param criterion The pointer to the function that implements the sorting criterion of the list.
+ * That function accepts two integer parameters and returns a boolean value.
+ * @param needle The value to find within the haystack.
+ * @return The index of the `needle` within the list if it was found or the position where the needle need to
+ * be inserted into the sorted list if it is not included in the list. The insertion position is 
+ * expressed as index with negative sign, so that the value can be inserted at index (-1 * result).
+ */
+int binary_search_list(IntList haystack, criterion_fn criterion, int needle) {
+    if (!list_is_valid(haystack)) {
+        return -1;
+    }
+    
+    return binary_search_list_limited(haystack, list_get_size(haystack), criterion, needle);
+}
+
+/**
+ * Searches the given needle within the given haystack up the given length using binary search approach.
+ * 
+ * @param haystack The sorted list in which the `needle` is searched.
+ * @param length The number of items to consider starting from the beginning of the haystack.
+ * If the haystack contains more items, the remaining items are omitted from the search. If it contains
+ * less items, the number of items are clipped to the size of the haystack.
+ * @param criterion The pointer to the function that implements the sorting criterion of the list.
+ * That function accepts two integer parameters and returns a boolean value.
+ * @param needle The value to find within the haystack.
+ * @return The index of the `needle` within the list if it was found or the position where the needle need to
+ * be inserted into the sorted list if it is not included in the list. The insertion position is 
+ * expressed as index with negative sign, so that the value can be inserted at index (-1 * result).
+ */
+int binary_search_list_limited(IntList haystack, int length, criterion_fn criterion, int needle) {
+    if (!list_is_valid(haystack) || criterion == 0) {
+        return -1;
+    }
+    
+    int list_size = list_get_size(haystack);
+    if (length > list_size) {
+        length = list_size;
+    }
+    
+    if (length <= 0) {
+        return -1;
+    }
+    
+    int left = 0;
+    int right = length - 1;
+    
+    while (left <= right) {
+        int mid = left + (right - left) / 2;
+        int mid_value = list_get_at(haystack, mid);
+        
+        if (mid_value == needle) {
+            return mid;
+        }
+        
+        if (criterion(mid_value, needle)) {
+            left = mid + 1;
+        } else {
+            right = mid - 1;
+        }
+    }
+    
+    return -left;
+}
+
+/* ARRAY VARIANT */
+
+/**
+ * Searches the given needle within the given haystack using binary search approach.
+ *  
+ * @param haystack The sorted list in which the `needle` is searched.
+ * @param length The length of the haystack array.
+ * @param criterion The pointer to the function that implements the sorting criterion of the list.
+ * That function accepts two integer parameters and returns a boolean value.
+ * @param needle The value to find within the haystack.
+ * @return The index of the `needle` within the list if it was found or the position where the needle need to
+ * be inserted into the sorted list if it is not included in the list. The insertion position is 
+ * expressed as index with negative sign, so that the value can be inserted at index (-1 * result).
+ */
+int binary_search_array(int haystack[], int length, criterion_fn criterion, int needle) {
+    return -1;
+}