#include <stdio.h>
#include <math.h>
int reverse_number(int num) {
int reminder = 0, reverse = 0;
while (num != 0) {
reminder = num % 10;
reverse = reverse * 10 + reminder;
num /= 10;
}
return reverse;
}
int delete_digit(int num, int n_digit) {
int rev_new_num = 0;
int l = log10(num) + 1;
for (int i = 0; num != 0; i++) {
int digit = num % 10;
num = num / 10;
if (i != l - n_digit) {
rev_new_num = (rev_new_num * 10) + digit;
}
}
return reverse_number(rev_new_num);
}
int main() {
int num = 37598;
printf("%i\n", delete_digit(num, 3));
printf("%i\n", delete_digit(num, 1));
printf("%i\n", delete_digit(num, 5));
}
/*
run:
3798
7598
3759
*/