控制台画圆

　　书上看到一个画空心圆的题，于是用C++写了一个实心圆...

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

using namespace std;

class DrawCircle {
public:
	void drawCircle(int r) {
		int x, y;
		int params_1 = 2;
		int params_2 = 5;

		for (y = 0; y < r; y++) {
			x = -(int)sqrt(2 * y * r - y * y) + r;
			for (int i = 0; i < params_1*x; i++)
				cout << ' ';
			cout << '*';
			for (int i = ((int)sqrt(2 * y * r - y * y) + r - x)*params_1 + params_2; i >= 0; i--)
				cout << (i % 2 == 0 ? '*' : i % 3 == 0 ? '$' : '%');
			cout << '*' << endl;
		}

		for (; y >= 0; y--) {
			x = -(int)sqrt(2 * y * r - y * y) + r;
			for (int i = 0; i < params_1*x; i++)
				cout << ' ';
			cout << '*';
			for (int i = ((int)sqrt(2 * y * r - y * y) + r - x)*params_1 + params_2; i >= 0; i--)
				cout << (i % 2 == 0 ? '*' : i % 3 == 0 ? '$' : '%');
			cout << '*' << endl;
		}
	}
};

int main()
{
	DrawCircle dc;
	int r = 12;

	dc.drawCircle(r);
	getchar();
    return 0;
}

　　运行结果：

　　更简洁一点的代码：

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

using namespace std;

class DrawCircle {
public:
	void drawCircle(int r) {
		int x, y;
		int i;
		double params_1 = 2.5;

		for (y = 10; y >= -r; y--) {
			x = (int)sqrt(r * r - y * y);
			for (i = 0; i < 30 - params_1 * x; i++)
				cout << ' ';
			cout << '*';
			for (; i < 30 + params_1 * x; i++)
				cout << (i % 2 == 0 ? '*' : i % 3 == 0 ? '$' : '%');
			cout << '*' << endl;
		}
	}
};

int main()
{
	DrawCircle dc;
	int r = 10;

	dc.drawCircle(r);
	getchar();
    return 0;
}

　　运行截图：