From 75f2d0fc9ad0f4313507d6c9288f767d81bf90cd Mon Sep 17 00:00:00 2001
From: Fegor <fegor@fegor.com>
Date: Tue, 23 May 2023 18:39:11 +0200
Subject: [PATCH] Reto #21 - C

---
 .../c/fegorama.c"                             | 52 +++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 "Retos/Reto #21 - N\303\232MEROS PRIMOS GEMELOS [Media]/c/fegorama.c"

diff --git "a/Retos/Reto #21 - N\303\232MEROS PRIMOS GEMELOS [Media]/c/fegorama.c" "b/Retos/Reto #21 - N\303\232MEROS PRIMOS GEMELOS [Media]/c/fegorama.c"
new file mode 100644
index 0000000000..a6be7868d9
--- /dev/null
+++ "b/Retos/Reto #21 - N\303\232MEROS PRIMOS GEMELOS [Media]/c/fegorama.c"	
@@ -0,0 +1,52 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int isPrime(int n) 
+{
+    if (n < 3 || n == 4)
+    {
+        return 0;
+    }
+
+    int max = n / 2;
+
+    for (int i=2; i < max; i++)
+    {
+        if (n % i == 0)
+            return 0;
+    }
+
+    return 1;
+}
+
+int main(int args, char** argv)
+{
+    int rg, diff, ant = 0;
+
+    if (args != 2) 
+    {
+        printf("Debe introducir el rango máximo.");
+        return 1;
+    }
+
+    rg = atoi(argv[1]);
+
+    if (rg > 4) {
+        printf("(3, 5)");
+    } else 
+        return 0;
+
+    for (int i=4; i <= rg; i++) {
+        if (isPrime(i)) {
+            diff = i - ant;
+
+            if (diff == 2) {
+                printf(", (%d, %d)", ant, i);                
+            }
+            
+            ant = i;
+        }
+    }
+    
+    return 0;
+}