--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Looping.c	Tue Feb 15 13:47:19 2011 +0900
@@ -0,0 +1,41 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <sys/time.h>
+
+typedef struct {
+	int n0;
+} Looping;
+
+int calc(Looping *s, int n){
+	int n1 = s->n0 + (1 - 2*(n%2));
+	s->n0 = n;
+	return n1;
+}
+
+double gettimeofday_sec()
+{
+  struct timeval tv;
+  gettimeofday(&tv, NULL);
+  return tv.tv_sec + (double)tv.tv_usec*1e-6;
+}
+
+int main(){
+  Looping *o;
+  unsigned c;
+  int n = 1;
+  double t1, t2;
+
+  o = (Looping *)malloc(sizeof(Looping));
+  o->n0 = 0;
+
+  t1 = gettimeofday_sec();
+  for(c=0;c<INT_MAX;c++){
+    n = calc(o, n);
+  }
+  t2 = gettimeofday_sec();
+  printf("%d\nC\t%f\n", n, t2 - t1);
+
+  free(o);
+  return 0;
+}