C primer plus 第八章练习5：

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我是靠谱客的博主热心板栗，这篇文章主要介绍C primer plus 第八章练习5：，现在分享给大家，希望可以做个参考。

修改程序清单8.4中的猜测程序，使其使用更加智能的猜测策略，例如，程序最初猜50，让其询问
用户该猜大，小还是正确。如果该猜值小，则令下一次猜测值为50和100值，也就是75，如果75大，
则下一次猜测75与50之间的值等等，使用这种二分搜索策略，起码如果用户没有欺骗，该程序很快
会获得正确答案。

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/*#include <stdio.h>
#include <windows.h>
int main(void)
{
int guess = 50;
int gue = 50;
char xz;
printf("Pick an integer from 1 to 100. I will try to guess it.n");
printf("Respond with a y if my guess is right and with an n if it is wrong.n");
printf("Uh...is your number %d?n", guess);
while ((xz = getchar()) != 'y') {
switch (xz) {
case 'd':gue = (0 + gue) / 2;
printf("%dn", gue);
break;
case 'x':gue = (gue + 100) / 2;
printf("%dn", gue);
break;
default: break;
}
}
printf("I knew I could do it!n");
system("pause");
return 0;
}*/

以上程序还是有瑕疵。。

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#include <stdio.h>
#include <windows.h>
int main(void)
{
int low, high, mid;
low = 1, high = 100, mid = 50;
char xz;
printf("Pick an integer from 1 to 100. I will try to guess it.n");
printf("Respond with a y if my guess is right and with an n if it is wrong.n");
printf("输入'q'退出，请输入'd'表明此数太大了，或'x'表明此数太小了: n");
printf("Uh...is your number %d?n", mid);
while ((xz = getchar()) != 'q' && low < high) {
if(xz == 'y'){
printf("正确！n");
}else if (xz == 'd') {
printf("太大了吧！n");
high = mid - 1;
}else if(xz == 'x') {
printf("太小了吧！n");
low = mid + 1;
}
mid = (high + low) / 2;
printf("是%d吗，太大输入d，太小输入x，正确输入y。n", mid);
while ((xz = getchar()) != 'n') {
continue;
}
}
printf("I knew I could do it!n");
system("pause");
return 0;
}