WrongSubtraction.cpp

/* Little girl Tanya is learning how to decrease a number by one, but she does it wrong with a number consisting of two or more digits. 
Tanya subtracts one from a number by the following algorithm:

if the last digit of the number is non-zero, she decreases the number by one;
if the last digit of the number is zero, she divides the number by 10 (i.e. removes the last digit).
You are given an integer number n
. Tanya will subtract one from it k
 times. Your task is to print the result after all k
 subtractions.

It is guaranteed that the result will be positive integer number.

Input
The first line of the input contains two integer numbers n
 and k
 (2≤n≤109
, 1≤k≤50
) — the number from which Tanya will subtract and the number of subtractions correspondingly.

Output
Print one integer number — the result of the decreasing n
 by one k
 times.

It is guaranteed that the result will be positive integer number. */

#include <iostream>

using namespace std;

int main()
{
    int n, k;
    cin >> n >> k;

    for(int i = 0; i < k; i++){
        if(n % 10 != 0){
            n--;
        }else{
            n = n / 10;
        }
    }
    cout << n;

    return 0;
}