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Diffstat (limited to 'rushs/tinyprintf/binary_search_ptr')
-rw-r--r--rushs/tinyprintf/binary_search_ptr/bsearch.c38
-rw-r--r--rushs/tinyprintf/binary_search_ptr/bsearch.h16
2 files changed, 54 insertions, 0 deletions
diff --git a/rushs/tinyprintf/binary_search_ptr/bsearch.c b/rushs/tinyprintf/binary_search_ptr/bsearch.c
new file mode 100644
index 0000000..bdc189c
--- /dev/null
+++ b/rushs/tinyprintf/binary_search_ptr/bsearch.c
@@ -0,0 +1,38 @@
+#include "bsearch.h"
+
+#include <stddef.h>
+
+int *binary_search(int *begin, int *end, int elt)
+{
+ if (begin == end)
+ {
+ return begin;
+ }
+ if (begin > end)
+ {
+ if (elt > *begin)
+ {
+ return begin + 1;
+ }
+ return begin;
+ }
+
+ size_t m = (end - begin) / 2;
+
+ if (begin[m] == elt)
+ {
+ return begin + m;
+ }
+
+ if (begin[m] > elt)
+ {
+ return binary_search(begin, begin + m, elt);
+ }
+
+ if (m == 0)
+ {
+ m++;
+ }
+
+ return binary_search(begin + m, end, elt);
+}
diff --git a/rushs/tinyprintf/binary_search_ptr/bsearch.h b/rushs/tinyprintf/binary_search_ptr/bsearch.h
new file mode 100644
index 0000000..e011744
--- /dev/null
+++ b/rushs/tinyprintf/binary_search_ptr/bsearch.h
@@ -0,0 +1,16 @@
+#ifndef BSEARCH_H_
+#define BSEARCH_H_
+
+/*
+** Search `elt` in the memory range of [`begin` - `end`[.
+** `begin` is a pointer to the first element.
+** `end` is a pointer **AFTER** the last element.
+** The elements in the range [`begin` - `end`[ are sorted in ascending order.
+** If the range is empty, `begin` == `end`.
+** `begin` and `end` can't be `NULL`.
+** Returns a pointer to the element if found, or a pointer to the memory
+** location where the element could be inserted to keep the array sorted.
+*/
+int *binary_search(int *begin, int *end, int elt);
+
+#endif /* !BSEARCH_H_ */