UVa 1587

Box.cpp

#include <stdio.h>
#include <vector>

using namespace std;

class Rectangle
{
public:
    int width = 0;
    int height = 0;
    int appearTimes = 1;

    Rectangle() {}
    Rectangle(int w, int h) { width = w, height = h; }
};

bool IsSameRectangle(Rectangle &rectangle1, Rectangle &rectangle2)
{
    return (rectangle1.width == rectangle2.width && rectangle1.height == rectangle2.height) ||
           (rectangle1.height == rectangle2.width && rectangle1.width == rectangle2.height);
}

bool IsAbleAddNewRectangle(Rectangle &currentRectangle, std::vector<Rectangle> &rectangles)
{
    for (auto &rectangle : rectangles)
    {
        if (rectangle.appearTimes == 2)
        {
            continue;
        }

        if (IsSameRectangle(rectangle, currentRectangle))
        {
            rectangle.appearTimes++;
            return false;
        }
    }
    return true;
}

bool FitTwoRectangles(Rectangle &topRectangle, Rectangle &rightRectangle, Rectangle forwardRectangle)
{
    if (topRectangle.width == rightRectangle.width)
    {
        auto estimateForwardRectangle = Rectangle(rightRectangle.height, topRectangle.height);
        return IsSameRectangle(estimateForwardRectangle, forwardRectangle);
    }
    else if (topRectangle.width == rightRectangle.height)
    {
        auto estimateForwardRectangle = Rectangle(rightRectangle.width, topRectangle.height);
        return IsSameRectangle(estimateForwardRectangle, forwardRectangle);
    }
    return false;
}

bool IsAllRectangleAbleMakeBox(vector<Rectangle> &rectangles)
{
    if (rectangles.size() != 3)
    {
        return false;
    }

    auto topRectangle = rectangles[0];
    auto rightRectangle = rectangles[1];
    auto forwardRectangle = rectangles[2];

    return FitTwoRectangles(topRectangle, rightRectangle, forwardRectangle) ||
           FitTwoRectangles(topRectangle, forwardRectangle, rightRectangle);
}

int main()
{
    auto T = 0;
    auto rectangle = Rectangle{};
    auto rectangles = vector<Rectangle>{};
    while (~scanf("%d%d", &rectangle.width, &rectangle.height))
    {
        T++;
        if (IsAbleAddNewRectangle(rectangle, rectangles))
        {
            rectangles.push_back(rectangle);
        }

        if (T == 6)
        {
            T = 0;
            printf("%s\n", IsAllRectangleAbleMakeBox(rectangles) ? "POSSIBLE" : "IMPOSSIBLE");
            rectangles.clear();
        }
    }
    return 0;
}