package recursion1;

/*
 * Given a non-negative int n, return the count of the occurrences of 7 as a
 * digit, so for example 717 yields 2. (no loops). Note that mod (%) by 10
 * yields the rightmost digit (126 % 10 is 6), while divide (/) by 10 removes
 * the rightmost digit (126 / 10 is 12).
 * 
 * count7(717) -> 2
 * count7(7) -> 1
 * count7(123) -> 0
 */

public class Count7Test {

	public static void main(String[] args) {
		Count7Test test = new Count7Test();
		System.out.println(test.count7(717));
		System.out.println(test.count7(7));
		System.out.println(test.count7(123));
	}
	
	public int count7(int n) {
	    if (n == 0) {
	        return 0;
	    } else if (n % 10 == 7) {
	        return 1 + count7(n / 10);
	    } else {
	        return count7(n / 10);
	    }
	}
}
@@ -307,16 +307,17 @@
 t7(717) 
+-
 -%3E 2%0A * 
@@ -326,16 +326,17 @@
 unt7(7) 
+-
 -%3E 1%0A * 
@@ -347,16 +347,17 @@
 t7(123) 
+-
 -%3E 0%0A */
@@ -778,8 +778,9 @@
   %7D%0A%09%7D%0A%7D
+%0A

Update Count7Test.java