use C program Write a function digit(n, k) that returns the k th digit (from the right) in n (a positive integer). For example digit(829, 1) returns 9, digit(829, 2) returns 2 and digit(829, 3) returns 8. if k is greater than the number of digits in n , have the function return 0.

Sure, here's a C program that defines a function `digit(n, k)` that returns the `k`th digit (from the right) in `n` (a positive integer):

#include <stdio.h>

int digit(int n, int k) {
    int count = 0;
    while (n > 0) {
        count++;
        if (count == k) {
            return n % 10;
        }
        n /= 10;
    }
    return 0;
}

int main() {
    int n = 829;
    int k = 1;
    printf("The %dth digit (from the right) in %d is %d\n", k, n, digit(n, k));
    
    k = 2;
    printf("The %dth digit (from the right) in %d is %d\n", k, n, digit(n, k));
    
    k = 3;
    printf("The %dth digit (from the right) in %d is %d\n", k, n, digit(n, k));
    
    k = 4;
    printf("The %dth digit (from the right) in %d is %d\n", k, n, digit(n, k));
    
    return 0;
}

This program defines a function `digit(n, k)` that takes two arguments: `n` (the positive integer) and `k` (the index of the digit to return, from the right). The function works by counting the number of digits in `n` as it repeatedly divides `n` by 10. If `count` equals `k`, the function returns the last digit of `n`. If `count` exceeds the number of digits in `n`, the function returns 0.

I hope that helps! Let me know if you have any further questions.