add counting_sort

Author: BaseMax

Diff for: a.exe

@@ -0,0 +1,39 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+void counting_sort(int *arr, int n) {
+    int max = arr[0];
+    for (int i = 1; i < n; i++) {
+        if (arr[i] > max) {
+            max = arr[i];
+        }
+    }
+    int *count = (int *)malloc(sizeof(int) * (max + 1));
+    for (int i = 0; i <= max; i++) {
+        count[i] = 0;
+    }
+    for (int i = 0; i < n; i++) {
+        count[arr[i]]++;
+    }
+    int j = 0;
+    for (int i = 0; i <= max; i++) {
+        while (count[i] > 0) {
+            arr[j++] = i;
+            count[i]--;
+        }
+    }
+    free(count);
+}
+
+int main(int argc, char** argv) {
+    int arr[] = { 5, 4, 3, 2, 1 };
+    int n = sizeof(arr) / sizeof(arr[0]);
+
+    counting_sort(arr, n);
+
+    for (int i = 0; i < n; i++) {
+        printf("%d ", arr[i]);
+    }
+
+    return 0;
+}