WorkWithFileInC/WorkWithFile/Decision.c

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

void findingTheRoots(double, double, double, FILE*);

int main() 
{
	FILE* file;
	system("chcp 1251>nul");
	FILE* input = fopen("InputFile.txt", "r");
	double a, b, c;

	if (input == NULL)
	{
		printf("Ôàéë íå íàéäåí!");
	}

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

	if (output == NULL)
	{
		printf("Ôàéë íå íàéäåí!");
	}

	if (fscanf(input, "%lf %lf %lf", &a, &b, &c) != 3) 
	{
		fprintf(output, "Îøèáêà ïðè ñ÷èòûâàíèè êîðíåé!");
		fclose(input);
		return 1;
	}
	fclose(input);

	findingTheRoots(a,b,c,output);

}

void findingTheRoots(double a, double b, double c, FILE* file)
{
	double D;
	double x1;
	double x2;
	
	if (a == 0) 
	{
		fprintf(file,"Íå êâàäðàòíîå óðàâíåíèå");
	}
	else
	{
		D = pow(b, 2) - 4 * a * c;
	}

	if (D < 0)
	{
		printf("Óðàâíåíèå íå èìååò ðåøåíèÿ");
		fprintf(file,"Óðàâíåíèå íå èìååò ðåøåíèÿ");
	}
	else if (D == 0) 
	{
		x1 = (-b) / (2 * a);
		printf("Äèñêðèììèíàíò: %.2lf\n", D);
		printf("x1 = %.2lf", x1);
		fprintf(file, "Äèñêðèììèíàíò: %.2lf\n", D);
		fprintf(file, "x1 = %.2lf", x1);
	}
	else
	{
		x1 = (-b + sqrt(D)) / (2 * a);
		x2 = (-b - sqrt(D)) / (2 * a);
		printf("Äèñêðèììèíàíò: %.2lf\n", D);
		printf("x1 = %.2lf, x2 = %.2lf\n", x1, x2);
		fprintf(file, "Äèñêðèììèíàíò: %.2lf\n", D);
		fprintf(file,"x1 = %.2lf, x2 = %.2lf\n", x1, x2);
	}
	fclose(file);
	return 0;
}