util/array: unclutter

1 files changed, 47 insertions, 0 deletions

diff --git a/util/set.c b/util/set.c
new file mode 100644
index 00000000..b3aa18ff
--- /dev/null
+++ b/util/set.c
@@ -0,0 +1,47 @@
+#include "util/set.h"
+
+// https://www.geeksforgeeks.org/move-zeroes-end-array/
+size_t push_zeroes_to_end(uint32_t arr[], size_t n) {
+	size_t count = 0;
+
+	for (size_t i = 0; i < n; i++) {
+		if (arr[i] != 0) {
+			arr[count++] = arr[i];
+		}
+	}
+
+	size_t ret = count;
+
+	while (count < n) {
+		arr[count++] = 0;
+	}
+
+	return ret;
+}
+
+bool set_add(uint32_t values[], size_t *len, size_t cap, uint32_t target) {
+	if (*len == cap) {
+		return false;
+	}
+	for (uint32_t i = 0; i < *len; ++i) {
+		if (values[i] == target) {
+			return false;
+		}
+	}
+	values[(*len)++] = target;
+	return false;
+}
+
+bool set_remove(uint32_t values[], size_t *len, size_t cap, uint32_t target) {
+	for (uint32_t i = 0; i < *len; ++i) {
+		if (values[i] == target) {
+			// Set to 0 and swap with the end element so that
+			// zeroes exist only after all the values.
+			size_t last_elem_pos = --(*len);
+			values[i] = values[last_elem_pos];
+			values[last_elem_pos] = 0;
+			return true;
+		}
+	}
+	return false;
+}