package math;

/**

* Given a number print the next big number using the same digits.

*

* Link: http://www.geeksforgeeks.org/find-next-greater-number-set-digits/

*

* @author shivam.maharshi

*/

public class NextBigNumber {

static int[] num;

public static void getNext() {

if (num == null) {

System.out.println("Invalid input.");

return;

}

if (num.length == 1) {

System.out.println(num[0]);

return;

}

int i = num.length - 2;

outer: while (i >= 0) {

for (int j = num.length - 1; j > i; j--) {

if (num[i] < num[j]) {

swap(i, j);

break outer;

}

if (i == 0 && j == 1) {

System.out.println("This is the maximum number.");

return;

}

}

i--;

}

int j = num.length - 1;

++i;

while (i < j) {

swap(i, j);

--j;

++i;

}

printNum(num);

}

private static void swap(int i, int j) {

int temp = num[i];

num[i] = num[j];

num[j] = temp;

}

private static void printNum(int[] num) {

String res = "";

for (int i = 0; i < num.length; i++) {

res += num[i];

}

System.out.println(res);

}

public static void main(String[] args) {

NextBigNumber.num = new int[] { 1, 2, 3, 4, 5 };

int i = 120;

while (i != 0) {

--i;

System.out.println(i);

NextBigNumber.getNext();

}

}

}