수학 평면좌표 단원

math.cpp

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

/** Error Messages **/
const char undefinedCmd[100] = "Undefined Command.";

void swap (int *a, int *b) {
  int tmp = *a;
  *a = *b;
  *b = tmp;
}

char boolToSignal (bool signal) {
  return signal ? '+' : '-';
}

int absValue (int value) {
  return value > 0 ? value : -value;
}

struct Point {
  int x, y;
  char name;

  void initialize (int X, int Y, char NAME) {
    x = X, y = Y, name = NAME;
  }

  char* repr () {
    char* stringValue = (char *) malloc(sizeof(char) * 100);
    sprintf(stringValue, "%c(%d, %d)", name, x, y);
    return stringValue;
  }

  void output () {
    printf("%c(%d, %d)\n", name, x, y);
  }

  void symmetricTrsp (char base) {
    switch (base) {
      case 'x':
        y = -y;
        break;
      case 'y':
        x = -x;
        break;
      case 'o':
        x = -x, y = -y;
        break;
      case '=':
        swap(&x, &y);
        break;
      default:
        printf("%s\n", undefinedCmd);
    }
  }

  void parallelTlsl (int amountX, int amountY) {
    x += amountX, y += amountY;
  }

  double distanceToPoint (Point p) {
    return sqrt(pow(x - p.x, 2) + pow(y - p.y, 2));
  }
};

struct Equation {
  int xCof, yCof, constVal;
  bool ySgn, constSgn; // true -> +, false -> -

  void initialize (int XCof, int YCof, int ConstVal) {
    xCof = XCof, yCof = YCof, constVal = ConstVal;
    ySgn = xCof > 0, constSgn = ConstVal > 0;
  }

  char* repr () {
    char* stringValue = (char *) malloc(sizeof(char) * 100);
    int absY = absValue(xCof), absConst = absValue(constVal);
    sprintf(stringValue, "%dx %c %dy %c %d = 0",
      xCof, boolToSignal(ySgn), absY, boolToSignal(constSgn), absConst);
    return stringValue;
  }

  void output () {
    int absY = absValue(yCof), absConst = absValue(constVal);
    printf("%dx %c %dy %c %d = 0\n",
      xCof, boolToSignal(ySgn), absY, boolToSignal(constSgn), absConst);
  }

  double distanceToPoint (Point p) {
    double dist = absValue(p.x * xCof + p.y * yCof + constVal) / (double) sqrt(xCof * xCof + yCof * yCof);
    return dist;
  }
};

int main () {
  Point a;
  a.initialize(3, 3, 'A');

  Point b;
  b.initialize(5, 9, 'B');

  /* Print Distance From Point A To Point B */
  printf("점 %s와 점 %s 간의 거리 : %.2lf\n", a.repr(), b.repr(), a.distanceToPoint(b));

  Equation c;
  c.initialize(3, 2, 5);

  printf("점 A를 x축에 대해 대칭이동 하기 전 좌표 : %s\n", a.repr());
  a.symmetricTrsp('x');
  printf("점 A를 x축에 대해 대칭이동 한 후의 좌표 : %s\n", a.repr());
  return 0;
}