files_c/files/FileName.c

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <malloc.h>

int main()
{
    FILE* file;
    //char buffer[128];
    system("chcp 1251 < nul");

    FILE* input = fopen("input.txt", "r");

    if (input == NULL)
    {
        printf("Failed to open input file");
        return 1;
    }

    FILE* output = fopen("output.txt", "w");

    if (output == NULL)
    {
        printf("Failed to open output file");
        return 1;
    }

    float a, b, c;
    if (fscanf(input, "%f %f %f", &a, &b, &c) != 3)
    {

        fprintf(output, "A lot of many numbers");
        fclose(input);
        return 1;
    }
    if (a == 0)
    {
        fprintf(output, "Not have exc => a = 0");
        fclose(input);
        return 1;
    }
    fclose(input);

    float discriminant = b * b - 4 * a * c;



    if (discriminant > 0) //Äâà äåéñòâèòåëüíûõ êîğíÿ
    {
        float x1 = (-b + sqrt(discriminant)) / (2 * a);
        float x2 = (-b - sqrt(discriminant)) / (2 * a);
        fprintf(output, "Discriminant:\n%.1f\n", discriminant);
        fprintf(output, "Resultat:\nx1 = %.1f\nx2 = %.1f\n", x1, x2);
    }
    else if (discriminant == 0) //Îäèí äåéñòâèòåëüíûé êîğåíü
    {
        float x = -b / (2 * a);
        fprintf(output, "Discriminant:\n%.1f\n", discriminant);
        fprintf(output, "Resultat:\nx = %.1f\n", x);
    }
    else if (discriminant < 0)
    {
        fprintf(output, "Not have exc => ");
        fprintf(output, "Discriminant:\n%.1f\n", discriminant);
    }
    fclose(output);
    return 0;
}