Aggiorna test.c

test.c

@@ -1,17 +1,14 @@
-int fibonacci( void ) {
-   int n = 1000000;
-   if ( n <= 1 ) return n;
-   return fibonacci( n - 1 ) + fibonacci ( n - 2);
-}
+#include <stdint.h>
 
-/*
-int main(int argc, char *argv[]) {
-    if (argc != 2) {
-        printf("Usage: %s <number>\n", argv[0]);
-        return 1;
+uint64_t fibonacci( void ) {
+    const int n = 500000;
+    uint64_t a = 0, b = 1, c;
+
+    for (int i = 2; i <= n; i++) {
+        c = a + b;
+        a = b;
+        b = c;
     }
-    int n = atoi(argv[1]);
-    printf("%d\n", fibonacci(n));
-    return 0;
+
+    return b;
 }
-*/