c语言求两个数的最大公约数

秒速五厘米 2022-09-30 13:48 238阅读 0赞

从键盘输入两个整数，输出两个整数的最大公约数。

1.程序风格良好(使用自定义注释模板)

2.使用三种算法解决问题

#include "stdio.h"
    struct common{}; 
    int m;
    int n;
    void div();//辗转相除法
    void sub();//相减法
    int exh();//穷举法
    
    //辗转相除法
    void div()
    {
    	int x;
    	int a, b;
    	a = m;
    	b = n;
    	if (a > b)
    	{
    		x = a%b;
    	}
    	else
    	{
    		x = a;
    		a = b;
    		b = x;
    		x = a%b;
    	}
    	while (x != 0)
    	{
    		a = b;
    		b = x;
    		x = a%b;
    	}
    	printf_s("最大公约数是%d。\n", b);
    }
    
    //相减法
    void sub()
    {
    	int a, b;
    	a = m;
    	b = n;
    	while (a!=b)
    	{
    		if (a > b)
    		{
    			a = a - b;
    		}
    		else
    		{
    			b = b - a;
    		}
    	}
    	printf_s("最大公约数是%d。\n", a);
    }
    
    //穷举法
    int exh()
    {
    	int x, y=0;
    	int a, b;
    	a = m;
    	b = n;
    	if (a>b)
    	{
    		for  ( x = b; x > 0;  x--)
    		{
    			if (a%x == 0 && b%x == 0)
    			{
    				y = x;
    				printf_s("最大公约数是%d。\n", y);
    				return 0;
    			}
    		}
    	}
    	else
    	{
    		for  (x = a; x >  0; x--)
    		{
    			if (a%x == 0 && b%x == 0)
    			{
    				y = x;
    				printf_s("最大公约数是%d。\n", y);
    				return 0;
    			}
    		}
    	}
    	
    	return 0;
    }
    
    
    //主函数
    int main()
    {
    	int select = 1;
    	int i;
    	while (select)
    	{
    		printf_s("请输入两个数(并以英文逗号隔开)：");
    		scanf_s("%d,%d", &m, &n);
    		printf_s("\n");
    		printf_s("              *********************************************************\n");
    		printf_s("              #                                                       #\n");
    		printf_s("              #               求两数最大公约数                        #\n");
    		printf_s("              #                                                       #\n");
    		printf_s("              *********************************************************\n");
    		printf_s("              #                                                       #\n");
    		printf_s("              #       0.辗转相除法          1.相减法                  #\n");
    		printf_s("              #                                                       #\n");
    		printf_s("              #       2.穷举法              3.退出系统                #\n");
    		printf_s("              #                                                       #\n");
    		printf_s("              *********************************************************\n");
    		printf_s("\n");
    		printf_s("                    请选择您需要的操作序号(0-3)按回车确认:");
    		scanf_s("%d", &i);
    		printf_s("\n");
    		switch (i)
    		{
    		case 0:
    			div();
    			break;
    		case 1:
    			sub();
    			break;
    		case 2:
    			exh();
    			break;
    		case 3:
    			select = 0;
    			break;
    		default:
    			printf_s("请在0-3之间选择\n");
    			break;
    		}
    	}
    	return 0;
    }

最终效果图：

![SouthEast][]

![SouthEast 1][] ![SouthEast 2][]

[SouthEast]: /images/20220705/7c7a741cfabd4b66aa71518aa178dcf9.png
[SouthEast 1]: https://img-blog.csdn.net/20170322171142529?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvamFjb294/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast
[SouthEast 2]: /images/20220705/300457dbbc43487583ad60cdd4fa0ddf.png