lab AG |)yNu

#include "graphics.h"
#include <math.h>
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#define N 20
typedef struct {
    float x, y;
} punct;
typedef struct {
    punct p1, p2;
} dreapta;
punct P[N];
punct m;//pct-ul ancora
float thetas[N];
float theta_s[N];// thetas sorted
int indxs[N]; //indecsii p-ctelor P sortate dupa thetas sorted
using namespace std;
#define pi 3.14159265359
int gd, gm;
int n, i, j;
double r, x, y, xp, yp, fi;
float x_1, x_2, y_1, y_2; int x_max, y_max;//coord ecran
int xe(float x)// normalizarea coordonatei x
{
    return((int)floor((x - x_1) / (x_2 - x_1)*x_max));
}
int ye(float y)// normalizarea coordonatei y
{
    return((int)floor((y_2 - y) / (y_2 - y_1)*y_max));
}
void axe2D()
{
    setcolor(0);
    outtextxy(xe(x_2) - 20, ye(0) - 20, "x");
    outtextxy(xe(x_2) - 18, ye(0) - 7, ">");
    outtextxy(xe(0) - 15, ye(y_2) + 15, "y");
    outtextxy(xe(0) - 15, ye(0) - 15, "O");
    outtextxy(xe(0) - 1, ye(y_2), "^");
    line(xe(x_1), ye(0), xe(x_2), ye(0));
    line(xe(0), ye(y_1), xe(0), ye(y_2));
}
void grafic()
{
    char pct[10];
    for (int i = 0; i<N; i++)
    {
        sprintf(pct, "%d", i + 1);
        putpixel(xe(P[i].x) + 5, ye(P[i].y) + 5, 6);
        outtextxy(xe(P[i].x) - 15, ye(P[i].y) - 15, pct);
    }
}
int citire_puncte()
{
    for (int i = 0; i<N; i++)
    {
        //  printf("\np[%d].x=", i);
        //  scanf("%f", &P[i].x);
        P[i].x = rand() % 200 - 100;

        //  printf("\nP[%d].y=", i);
        //scanf("%f", &P[i].y);
        P[i].y = rand() % 200 - 100;
    }
    return 1;
}
int jos_stanga()
{
    int imin = 0, i;
    for (i = 0; i<N; i++) {
        if ((P[i].y<P[imin].y) || ((P[i].y == P[imin].y) && (P[i].x<P[imin].x)))
            imin = i;
    }
    cout << "imin = " << imin;
    return imin;
}
/*
void citire_ancora(punct& m)
{
printf("\nm.x=");
scanf("%f", &m.x);
printf("\nm.y=");
scanf("%f", &m.y);
}
*/
void atribuire_ancora(punct& m)
{
//  int imin = jos_stanga();
    int imin = rand() % N;
    m.x = P[imin].x;
    m.y = P[imin].y;
}
float theta(punct p1, punct p2)
{
    float dx = p2.x - p1.x;
    float dy = p2.y - p1.y;
    float theta = 0.f;
/*  if ((dx != 0) || (dy != 0))
    {
        float ay = fabs(dy);
        theta = ay / (ay + fabs(dx));
    }
    if (dx<0) theta = 2 - theta;
    else if (dy<0) theta = 4 + theta;
    theta = 90.f*theta;
    */
    theta = atan(dy / dx);
    return theta;
}
void compSClosedPath()
{
    for (int i = 0; i<N; i++)//calculeaza masura asociata punctelor fata de ,,ancora"
    {
        thetas[i] = 0.f;
        if ((P[i].x != m.x) && (P[i].y != m.y))
            thetas[i] = theta(m, P[i]);
        theta_s[i] = thetas[i];
    }
    float fTemp = 0.f;
    for (int i = 0; i<N - 1; i++)//sorteaza masurile thetas in theta_s
        for (int j = i + 1; j<N; j++)
            if (theta_s[j]<theta_s[i])
            {
                fTemp = theta_s[j];
                theta_s[j] = theta_s[i];
                theta_s[i] = fTemp;
            }
    for (int i = 0; i<N; i++)//gaseste indecsii p-ctelor P, asociati masurilor sortate
        for (int j = 0; j<N; j++)
            if (theta_s[i] == thetas[j])
            {
                indxs[i] = j;
                break;
            }
    for (int i = 0; i<N - 1; i++)//desenarea propriu-zisa a liniilor
    {
        if (i == 0)
            line(xe(m.x), ye(m.y), xe(P[indxs[i]].x), ye(P[indxs[i]].y));
        line(xe(P[indxs[i]].x), ye(P[indxs[i]].y), xe(P[indxs[i + 1]].x),
            ye(P[indxs[i + 1]].y));
    }
    line(xe(m.x), ye(m.y), xe(P[indxs[N - 1]].x), ye(P[indxs[N - 1]].y));
}
int main()
{
    time_t t;
    srand((unsigned)(time(&t)));
    printf("Limitele domeniului orizontal:\n");
//  printf("x1="); scanf("%f", &x_1); //x_1<0<x_2
    x_1 = -100;
    //printf("x2="); scanf("%f", &x_2);
    x_2 = 100;\
    printf("Limitele domeniului vertical:\n");
    //printf("y1="); scanf("%f", &y_1); //y_1<0<y_2
    y_1 = -100;
    //printf("y2="); scanf("%f", &y_2);
    y_2 = 100;
    citire_puncte();
    atribuire_ancora(m);
    initwindow(800, 600, "intersectii de segmente", 200, 200);
    x_max = getmaxx(); //nr. maxim de pixeli pe coord. x
    y_max = getmaxy();
    setbkcolor(14);
    cleardevice();
    axe2D();
    grafic();
    getch(); getch();
    compSClosedPath();
    getch(); getch();
    return 1;
}