소스
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#include <iostream.h>
#include <math.h>

class point {
        int x1, y1;
public:
        point(int a, int b);
        int set_point(int x2, int y2);
        double GetDistance(int x, int y);
};

point::point(int a, int b)
{
        x1 = a;
        y1 = b;
}

double GetDistance(int x, int y)
{
        return sqrt((x2-x1) * (x2-x1) + (y2-y1) * (y2-y1));
}

int set_point(int x2, int y2)
{
        cout << "Enter a X2 :";
        cin >> x2;
        cout << "n";

        cout << "Enter a Y2 :";
        cin >> y2;
        cout << "n";

        return 1;
}
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에러메시지
C:C++1.cpp(20) : error C2065: 'x2' : undeclared identifier
C:C++1.cpp(20) : error C2065: 'x1' : undeclared identifier
C:C++1.cpp(20) : error C2065: 'y2' : undeclared identifier
C:C++1.cpp(20) : error C2113: pointer can only be subtracted from another pointer
C:C++1.cpp(20) : error C2113: pointer can only be subtracted from another pointer

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