From b75918cfe09743e73eba07b3daa6cd3748b6defc Mon Sep 17 00:00:00 2001
From: chf280902 <107817353+chf280902@users.noreply.github.com>
Date: Tue, 21 Jun 2022 07:23:33 +0900
Subject: [PATCH] Create gcd.d

---
 src/gcd.d | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 src/gcd.d

diff --git a/src/gcd.d b/src/gcd.d
new file mode 100644
index 0000000..f3acddb
--- /dev/null
+++ b/src/gcd.d
@@ -0,0 +1,38 @@
+#include <stdio.h>
+
+const int n = 1000;
+
+unsigned int Euclidean_gcd_rec(unsigned int x, unsigned int y){
+ if(x==0) return y;
+ return Euclidean_gcd_rec(y % x, x);
+}
+
+/*
+unsigned int Euclidean_gcd_itr(unsigned int x, unsigned int y){
+}
+
+unsigned int binary_gcd_rec(unsigned int x, unsigned int y){
+}
+
+unsigned int binary_gcd_itr(unsigned int x, unsigned int y){
+}
+*/
+
+
+int main(){
+  unsigned int i, j, c;
+
+
+  c = 0;
+  for(i = 1; i <= n; i++){
+    for(j = i + 1; j <= n; j++){
+      if(Euclidean_gcd_rec(i, j) == 1){
+        c++;
+      }
+    }
+  }
+  c = 2 * c + 1;
+
+  printf("%f\n", (double) c / (n * n));
+  return 0;
+}