GNU MP

1 files changed, 62 insertions, 0 deletions

diff --git a/gcd-gmp.c b/gcd-gmp.c
new file mode 100644
index 0000000..3de49de
--- /dev/null
+++ b/gcd-gmp.c
@@ -0,0 +1,62 @@
+/* 
+ * http://gmplib.org/
+ *
+ * gcc gcd-gmp.c -o gcd-gmp -lgmp
+ *
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <gmp.h>
+
+void gcd2(mpz_t r, mpz_t a1, mpz_t b1)
+{
+    mpz_t a, b;
+    mpz_init_set(a, a1);
+    mpz_init_set(b, b1);
+    while (mpz_sgn(b) != 0) {
+        mpz_set(r, b);    /* r = b; */
+        mpz_mod(b, a, b); /* b = a % b; */
+        mpz_set(a, r);    /* a = r; */
+    }
+    mpz_set(r, a);
+}
+
+void gcdn(mpz_t r, mpz_t a[], size_t n)
+{
+    size_t i;
+    mpz_set(r, a[0]);
+    for (i = 1; i < n; i++)
+        gcd2(r, r, a[i]); /* mpz_gcd ;-) */
+}
+
+
+int main (int argc, char *argv[])
+{
+    mpz_t *a, g;
+    int i, n;
+
+    if (argc > 1) {
+        n = argc - 1;
+        a = malloc(sizeof(mpz_t) * n);
+        if (NULL != a) {
+            for (i = 1; i <= n; i++)
+                mpz_init_set_str(a[i-1], argv[i], 10);
+
+            mpz_init(g);
+            gcdn(g, a, n);
+            mpz_out_str(NULL, 10, g);
+            printf("\n");
+
+            /* No need actually before exit */
+            mpz_clear(g);
+            for (i = 1; i <= n; i++)
+                mpz_clear(a[i-1]);
+            free(a);
+            return EXIT_SUCCESS;
+        }
+        return EXIT_FAILURE;
+    }
+    return EXIT_SUCCESS;
+}
+