一个猜测程序 用户心里选择一个数 让计算机询问用户是否正确并做控制 知道猜对数字（图）

#include "stdAfx.h"
#include "ctype.h"
#include "stdlib.h"

int main(void)
{
	int big(int max,int sum);
	int small(int max,int sum);

	char ch;
	int ave=50,sum=0,max;

	printf("The beginning Need little according to need big 'X' as 'D' if guess it please click 'Y'\n");
	printf("%d?\n",ave);

	while((ch=getchar())!=EOF)
	{
		if(ch!='\n')
		{
			switch(ch)
			{
				case 'y':
					printf("Done! please press CTRL + Z exit\n");
					break;

				case 'd':
					printf("Need big? good\n");
					printf("%d?\n",big(ave,sum));
					ave=big(ave,sum);
					break;

				case 'x':
					printf("Need small? good\n");
					printf("%d?\n",small(ave,sum));
					ave=small(ave,sum);
					break;
			}
		}
	}

	system("pause");
	return 0;
}

int big(int max,int sum)
{
	sum=(max+(max+50))/2;
	return sum;
}

int small(int max,int sum)
{
	sum=(max+(max-25))/2;
	return sum;
}