lucky numbers in c++

abranhe · web-flow · commit c04b3c5dbc09 · 2018-09-26T19:37:57.000-04:00
diff --git a/math/lucky_numbers.cpp b/math/lucky_numbers.cpp
@@ -0,0 +1,37 @@
+// Lucky number implementation
+// Carlos Abraham Hernandez
+// algorithms.abranhe.com/math/lucky-numbers
+
+#include <stdio.h> 
+#define bool int 
+  
+/* Returns 1 if n is a lucky no. ohterwise returns 0*/
+bool isLucky(int n) 
+{ 
+    static int counter = 2; 
+      
+    /*variable next_position is just for readability of 
+        the program we can remove it and use n only */
+    int next_position = n; 
+    if(counter > n) 
+        return 1; 
+    if(n%counter == 0) 
+        return 0;      
+      
+    /*calculate next position of input no*/
+    next_position -= next_position/counter; 
+      
+    counter++; 
+    return isLucky(next_position); 
+} 
+  
+/*Driver function to test above function*/
+int main() 
+{ 
+    int x = 7; 
+    if( isLucky(x) ) 
+        printf("%d is a lucky number.", x); 
+    else
+        printf("%d is not a lucky number.", x); 
+    getchar(); 
+} 
