// Program to test solutions to problem #7 on the cse143x midterm, autumn 2013.
// Fill in your solution to digitRange, then compile and run the program.

import java.util.*;

public class Test7 {
    public static int digitRange(int n) {
        // fill in your solution here
        // you can also rename the parameter above
    }

    // this is the sample solution
    public static int digitRange2(int n) {
        int min = n % 10;
        int max = n % 10;
        while (n > 0) {
            int digit = n % 10;
            n = n / 10;
            if (digit < min) {
                min = digit;
            }
            if (digit > max) {
                max = digit;
            }
        }
        return max - min;
    }

    private static int count, failCount;

    public static void main(String[] args) {
        for (int i = 0; i <= 3876254; i++) {
            test(i);
            if (failCount == 30) {
                break;
            }
        }

        if (failCount == 0) {
            System.out.println("passed all tests");
        } else {
            System.out.println("failed " + failCount + " of " + count +
                               " tests");
        }
    }

    public static void test(int n) {
        count++;
	int result2 = digitRange2(n);
        String exception = null;

        int result1 = 0;
        boolean fail = false;
	try {
	    result1 = digitRange(n);
        } catch (RuntimeException e) {
            int line = e.getStackTrace()[1].getLineNumber();
            exception = "threw " + e + " at line #" + line;
            fail = true;
        }
        if (!fail && result1 != result2) {
            fail = true;
        }
        if (fail) {
            System.out.println("failed for " + n);
            System.out.println("expected = " + result2);
            System.out.println("theirs   = " + result1);
            if (exception != null) {
                System.out.println(exception);
            }
            System.out.println();
            failCount++;
        }
    }
}