Untitled

#include <iostream>
#include <algorithm>
using namespace std;

bool isSmaller(string str1, string str2) {
 
    int n1 = str1.length(), n2 = str2.length();
    if (n1 != n2)
        return n1 < n2;

    for (int i = 0; i < n1; i++) {
        if (str1[i] < str2[i])
            return true;
        else if (str1[i] > str2[i]) 
            return false;
    }
    return false; 
}

string findDiff(string str1, string str2) {
   
    bool negative = false;
    if (isSmaller(str1, str2)) {
        swap(str1, str2);
        negative = true;
    }

    string result = ""; 
    int n1 = str1.length(), n2 = str2.length();

    reverse(str1.begin(), str1.end());
    reverse(str2.begin(), str2.end());

    int carry = 0;

    for (int i = 0; i < n2; i++) {
        int sub = ((str1[i] - '0') - (str2[i] - '0') - carry);
        if (sub < 0) {
            sub += 10;
            carry = 1;
        } else
            carry = 0;

        result.push_back(sub + '0');
    }

    for (int i = n2; i < n1; i++) {
        int sub = ((str1[i] - '0') - carry);
        if (sub < 0) {
            sub += 10;
            carry = 1;
        } else
            carry = 0;

        result.push_back(sub + '0');
    }
    while (!result.empty() && result.back() == '0')
        result.pop_back();

    reverse(result.begin(), result.end());

    if (negative)
        result = '-' + result;

    return result;
}

int main() {
    string str1, str2;

    cout << "Enter the first number: ";
    cin >> str1;

    cout << "Enter the second number: ";
    cin >> str2;

    cout << "Difference: " << findDiff(str1, str2) << endl;

    return 0;
}