IT school assignment for idiots

main.cpp

#include <iostream>
#include <fstream>
#include <string>
#include <math.h>
#include <limits>

using namespace std;

int octal_to_decimal(int octal) {
    int decimal_number = 0, i = 0, rem;
    while (octal != 0) {
        rem = octal % 10;
        octal /= 10;
        decimal_number += rem * pow(8, i);
        ++i;
    }
    return decimal_number;
}

int main() {
    ofstream result;
    result.open("C:\\Users\\Mateusz\\CLionProjects\\infa1\\wyniki6.txt");
    int n = 5000;
    ifstream file;
    file.open("C:\\Users\\Mateusz\\CLionProjects\\infa1\\dane.txt");
    string numbers[n];
    for (int i = 0; i < n; i++) getline(file, numbers[i]);
    // Task A
    int count = 0;
    for (int i = 0; i < n; i++) if (numbers[i].front() == numbers[i].back()) count++;
    result << "A" << endl;
    result << count << endl;
    // Task B
    result << "B" << endl;
    for (int i = 0; i < n; i++)
        if (to_string(octal_to_decimal(stoi(numbers[i]))).front() ==
            to_string(octal_to_decimal(stoi(numbers[i]))).back())
            result << numbers[i] << endl;
    // Task C
    result << "C" << endl;
    int accepted_count = 0;
    int min_accepted = INT_MAX;
    int max_accepted = 0;
    for (int i = 0; i < n; i++) {
        bool accepted = true;
        char previous = numbers[i][0];
        for (int a = 1; a < numbers[i].length(); a++) {
            if (numbers[i][a] < previous) accepted = false;
            previous = numbers[i][a];
        }
        if (accepted) {
            accepted_count++;
            int number = stoi(numbers[i]);
            if (number > max_accepted) max_accepted = number;
            if (number < min_accepted) min_accepted = number;
        }
    }
    result << accepted_count << endl;
    result << max_accepted << endl;
    result << min_accepted << endl;
    // Finish
    result.close();
    return 0;
}