this is a big fix, not a small fix

specials/binary_search.c

@@ -0,0 +1,25 @@
+// feed in a pointer to a function that takes 2 and returns (just like the )
+#include <stdlib.h>
+#include <stdio.h>
+
+int cmpfunc(const void *a, const void *b)
+{
+    const int *A = a, *B = b;
+    return (*A > *B) - (*A < *B);
+}
+
+int main(int argc, char const *argv[])
+{
+    int a[13] = {1, 2, 3, 7, 3, 9, 11, 13, 42, -1, 4, 52, 10};
+    qsort(a, 13, sizeof(int), cmpfunc);
+    for (int i = 0; i < 13; i++)
+        printf("%d ", a[i]);
+        printf("\n");
+    int at = 5;
+    int *here = (int *)bsearch(&at, a, 13, sizeof(int), cmpfunc);
+    if (here == NULL)
+        printf("no %d ", at);
+    else
+        printf("is %d ", *here);
+    return 0;
+}