#include <stdio.h>
// Finds the digit that comes before the target digit when scanning from right to left.
int find_previous_digit(int number, int target) {
int previous = -1; // To store the previous digit (default: -1 if not found)
int current;
while (number > 0) {
current = number % 10; // Extract the last digit
number /= 10; // Remove the last digit
if (current == target) {
if (number != 0) {
return number % 10; // Return the previous digit if target is found
}
}
previous = current; // Update the previous digit
}
return -1; // Return -1 if the target digit is not found
}
int main() {
int number = 8902741;
int target = 7;
int result = find_previous_digit(number, target);
if (result != -1) {
printf("The digit before %d in %d is %d.\n", target, number, result);
} else {
printf("The digit %d is not found or has no previous digit in %d.\n", target, number);
}
return 0;
}
/*
run:
The digit before 7 in 8902741 is 2.
*/
