cv7

a2/binary_search.h

@@ -0,0 +1,33 @@
+#ifndef BINARY_SEARCH_H
+#define BINARY_SEARCH_H
+
+#include <stddef.h>
+#include <math.h>
+#include <stdio.h>
+
+const int *binary_search(int value, const int *arr, size_t length) {
+    if (length == 0) {
+        return NULL;
+    }
+
+    size_t left = 0;
+    size_t right = length - 1;
+
+    while (left <= right) {
+        size_t middle = left + (right - left) / 2;
+
+        if (arr[middle] == value) {
+            return &arr[middle];
+        } else if (arr[middle] > value) {
+            if (middle == 0) {
+                break;
+            }
+            right = middle - 1;
+        } else {
+            left = middle + 1;
+        }
+    }
+    return NULL;
+}
+
+#endif