我编写的以下程序提示用户输入数字1 - 100.该程序具有来自用户必须猜测的随机数生成器的预选编号。如果用户的猜测太高或太低,程序将通知用户,直到用户的猜测是正确的。我的程序效果很好,但是当提示输入数字时,我必须在某些情况下输入数字四次或更多次以便程序提示我。有人可以告诉我还是帮我找错?
#include <iostream>
#include <ctime>//A user stated that using this piece of code would make a true randomization process.
#include <cstdlib>
using namespace std;
int main()//When inputing a number, sometimes the user has to input it more than once.
{
int x;
int ranNum;
srand( time(0));
ranNum = rand() % 100 + 1;
cout << "Please input your guess for a random number between 1 - 100.\n";
cin >> x;
while (x > ranNum || x < ranNum)
{
{
if (x > ranNum)
cout << "Your input was greater than the system's generated random number. Please try again.\n";
cin >> x;
if (x > 100 || x < 1)
cout << "Input invalid. Please input a number between 1 - 100.\n";
cin >> x;
}
{
if (x < ranNum)
cout << "Your input was less than the system's generated random number. Please try again.\n";
cin >> x;
if (x > 100 || x < 1)
cout << "Input invalid. Please input a number between 1 - 100.\n";
cin >> x;
}
{
if (x == ranNum)
cout << "You guessed right!\n";
}
}
return 0;
}
答案 0 :(得分:1)
您的括号位置错误。具有多行的if语句应采用
的形式if (condition)
{
code1
code2
code3
...
}
你拥有的是
{
if condition
code1
code2
code3
...
}
所以code1
只会在条件为真时运行,但code2
,code3
,其余的将无论如何运行。缩进在C ++中不算什么。我们可以(请永远不要这样做):
if (condition)
{
code1
code2
code3
}
所有三行都将在if语句中运行。
您的代码更正为括号位于正确的位置
while (x != ranNum)
{
if (x > ranNum)
{
cout << "Your input was greater than the system's generated random number. Please try again.\n";
cin >> x;
if (x > 100 || x < 1)
{
cout << "Input invalid. Please input a number between 1 - 100.\n";
cin >> x;
}
}
if (x < ranNum)
{
cout << "Your input was less than the system's generated random number. Please try again.\n";
cin >> x;
if (x > 100 || x < 1)
{
cout << "Input invalid. Please input a number between 1 - 100.\n";
cin >> x;
}
}
if (x == ranNum)
cout << "You guessed right!\n";
}
我还将while (x > ranNum || x < ranNum)
更改为while (x != ranNum)
,因为我们只想在x
不等于ranNum
时运行循环
答案 1 :(得分:0)
您没有正确使用if
语句:
{
if (x > ranNum)
cout << "Your input was greater than the system's generated random number. Please try again.\n";
cin >> x;
if (x > 100 || x < 1)
cout << "Input invalid. Please input a number between 1 - 100.\n";
cin >> x;
}
上述两个if
条件都不会影响任何内容,只会打印输出消息,并且周围的花括号也无用。当条件代码由多个单个语句组成时,您需要将其包装成花括号:
{
if (x > ranNum)
{
cout << "Your input was greater than the system's generated random number. Please try again.\n";
cin >> x;
}
if (x > 100 || x < 1)
{
cout << "Input invalid. Please input a number between 1 - 100.\n";
cin >> x;
}
}
此外,重复读取输入和执行范围检查的代码也没有意义。以下内容对我来说更直接:
int main()
{
int ranNum;
srand( time(0));
ranNum = rand() % 100 + 1;
cout << "Please input your guess for a random number between 1 - 100.\n";
cin >> x;
int x;
for (;;) // Endless loop
{
cin >> x;
if (x > 100 || x < 1)
{
cout << "Input invalid. Please input a number between 1 - 100.\n";
continue; // Jump to next iteration of the loop
}
if (x == ranNum)
{
cout << "You guessed right!\n";
break; // Leave the loop
}
if (x > ranNum)
cout << "Your input was greater than the system's generated random number. Please try again.\n";
else
cout << "Your input was less than the system's generated random number. Please try again.\n";
}
return 0;
}
答案 2 :(得分:0)
您的代码可能如下所示:
#include <iostream>
#include <ctime>//A user stated that using this piece of code would make a true randomization process.
#include <cstdlib>
using namespace std;
int main()//When inputing a number, sometimes the user has to input it more than once.
{
int x;
int ranNum;
srand(time(0));
ranNum = rand() % 100 + 1;
cout << "Please input your guess for a random number between 1 - 100.\n";
while (x > ranNum || x < ranNum)
{
cin >> x;
if (x > ranNum && x<=100 & x>=1) cout << "Your input was greater than the system's generated random number. Please try again.\n";
else if (x < ranNum && x<=100 & x>=1) cout << "Your input was smaller than the system's generated random number. Please try again.\n";
else if (x>=100 || x<=1) cout << "Input invalid. Please input a number between 1 - 100.\n";
}
cout << "You guessed right!\n";
return 0;
}
将来:
当你使用while循环时,它包含if语句。使用是正确的。另外,尝试嵌套if语句,但改为使用逻辑运算符。