1 files changed, 41 insertions, 0 deletions
diff --git a/reference/C/CONTRIB/SNIP/bitcnt_1.c b/reference/C/CONTRIB/SNIP/bitcnt_1.c
new file mode 100755
index 0000000..735c4e1
--- /dev/null
+++ b/reference/C/CONTRIB/SNIP/bitcnt_1.c
@@ -0,0 +1,41 @@
+/*
+**  Bit counter by Ratko Tomic
+*/
+
+int bit_count(long x)
+{
+        int n = 0;
+/*
+** The loop will execute once for each bit of x set, this is in average
+** twice as fast as the shift/test method.
+*/
+        if (x) do
+              n++;
+        while (0 != (x = x&(x-1)))
+              ;
+        return(n);
+}
+
+#ifdef TEST
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#define plural_text(n) &"s"[(1 == (n))]
+
+void main(int argc, char *argv[])
+{
+      long n;
+
+      while(--argc)
+      {
+            int i;
+
+            n = atol(*++argv);
+            i = bit_count(n);
+            printf("%ld contains %d bit%s set\n",
+                  n, i, plural_text(i));
+      }
+}
+
+#endif /* TEST */