Question

Write a program that takes in an integer in the range 20-98 as input. The output is a countdown starting from the integer, and stopping when both output digits are identical. So for example if you start at 98 and count down, the minute you reach 88 both numbers that make up 88 are identical and so you should quit looping.

Ex: If the input is: 93

the output is: 93 92 91 90 89 88


Ex: If the input is: 77

the output is: 77


Ex: If the input is: 15

or any number not between 20 and 98 (inclusive), the output is:

Input must be 20-98


For coding simplicity, follow each output number by a space, even the last one.


Use a while loop. Compare the digits; do not write a large if-else for all possible same-digit numbers (11, 22, 33, …, 88), as that approach would be cumbersome for larger ranges.


In C (not C++) please.


#include
< stdio.h >

int main(void) {


/* Type your code here. */


return 0;

}

Answer 1

Image 1: Input

integer x

x = Get next input

if x < 20 or x > 98

Put "Input must be 20-98" to output

else

while x/10 != x%10

Put x to output

Put " " to output

x = x - 1

Put x to output

Put " " to output

Image 2: Output

Input:

93

Output:

93 92 91 90 89 88