Odzemanje

#include <iostream>
#include <algorithm>
#include <string>
using namespace std;
int main()
{
    int y, m=0, n=0, q=0, j=0, l, i, a=0;
    string x;
    cin >> x;
    q = x.length();
    int BIGGIE[q], SMALL[q], finalHIT[q];
    for(i=0; i<q; i++)
    {
        BIGGIE[i] = (int)x[i] - (int)'0';
        SMALL[i] = (int)x[i] - (int)'0';
    }
    sort(SMALL, SMALL + q);
    sort(BIGGIE, BIGGIE + q);
    reverse(BIGGIE, BIGGIE + q);

    for(i=q-1; i>=0; i--)
    {
        if(BIGGIE[i]<SMALL[i])
        {
            BIGGIE[i]+=10;
            BIGGIE[i-1]--;
        }
        finalHIT[i] = BIGGIE[i]-SMALL[i];
    }
    while(finalHIT[a]==0)
    {
        a++;
        if(a==q-1){
            cout << "0";
            return 0;
        }
    }
    for(i=a; i<q; i++)
        cout << finalHIT[i];
    return 0;
}