Dante 7.14

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

float perimeter(float a, float b, float c)
{
    if(a<=0||b<=0||c<=0)return -1;
    if(a+b<=c)return -1;
    if(a+c<=b)return -1;
    if(b+c<=a)return -1;
    return a+b+c;
}

float distance(int x1, int y1,int x2, int y2)
{
    float w = sqrt(pow(x1-x2,2)+pow(y1-y2,2));
    return w;
}

float area(float a, float b, float c)
{
    if(a<=0||b<=0||c<=0)return -1;
    if(a+b<=c)return -1;
    if(a+c<=b)return -1;
    if(b+c<=a)return -1;
    float p;
    p = perimeter(a,b,c)/2;
    return sqrt(p*(p-a)*(p-b)*(p-c));

}

int main()
{
    int points[3][2];
    char string[100];
    float distances[3];
    for(int i = 0;i<3;i++)
    {
        printf("Podaj wspolrzedne punktu: ");
        fgets(string, 100, stdin);
        int input = sscanf(string,"(%d, %d)",&points[i][0],&points[i][1]);
        if(input!=2)
        {
            printf("Incorrect input");
            return 1;
        }
    }

    distances[0] = distance(points[0][0],points[0][1],points[1][0],points[1][1]);
    distances[1] = distance(points[1][0],points[1][1],points[2][0],points[2][1]);
    distances[2] = distance(points[2][0],points[2][1],points[0][0],points[0][1]);

    //float x = perimeter(6.315819027092632, 7.698365764946384, 1.0800501719980466);
    //printf("%f, %.2fA dobra",x,area(distances[0],distances[1],distances[2]));
    if(area(distances[0],distances[1],distances[2])!=-1)
        printf("%.2f",area(distances[0],distances[1],distances[2]));
    else
    {
        printf("Incorrect input");
        return 1;
    }

}