我正在尝试制作一个试图匹配＆＃34;密码的程序＆＃34;用户通过一次更改一个字符来引入，从1个字符长的字开始直到20个字符长的字。 这个程序只是作为循环等的练习。 我完全清楚我可以简单地写出＆＃34; cout＆lt;＆lt;密码;＆＃34;但这并不好玩;） 该程序在使用＆＃34; exit（0）;＆＃34;＆＃34;找到密码后停止。
所以这个奇怪的事情发生在我身上，如果密码超过一个字符长（通常我输入两个字符，因为如果密码很长，那么事情需要花费很多时间）程序保持不变即使在匹配密码并最终崩溃后也会发出哔哔声。 有趣的是，如果这个单词只有一个字符长，它会在匹配密码后停止发出哔哔声并且不会崩溃。
我已经读过，哔哔声可能是打印ASCII字符或类似的东西。我得到了它，但为什么它在程序找到密码后停止发出哔哔声？它仍在后台处理ASCII字符吗？
这里是代码（我很抱歉，如果它有点乱，但你可以从我的解释中了解它的作用，我希望）：
#include <iostream>
#include <string>
#include <cstdlib>
using namespace std;
string get_password()
{
//Asks for a password between 1 and 20 characters, both included.
string password;
do
{
cout << "Type a password: ";
getline( cin, password );
if ( password.length() > 20 )
{
cout << "The password is too long. The maximum number of characters allowed is 20." << endl;
}
else if ( password.length() < 1 )
{
cout << "The password is too short. The minimum number of characters allowed is 1." << endl;
}
} while ( password.length() < 1 || password.length() > 20 );
return password;
}
void guess(string password)
{
//Password 'cracking' happens here.
int i1, i2, i3, i4, i5, i6, i7, i8, i9, i10, i11, i12, i13, i14, i15, i16, i17, i18, i19, i20;
char c1, c2, c3, c4, c5, c6, c7, c8, c9, c10, c11, c12, c13, c14, c15, c16, c17, c18, c19, c20;
string s1, s2, s3, s4, s5, s6, s7, s8, s9, s10, s11, s12, s13, s14, s15, s16, s17, s18, s19, s20, ss;
for ( i1 = 1; i1 < 126; i1++ )
{
if ( i1 > 2 )
{
c1 = i1;
s1 = c1;
}
for ( i2 = 1; i2 < 126; i2++ )
{
if ( i2 > 2 )
{
c2 = i2;
s2 = c2;
}
for ( i3 = 1; i3 < 126; i3++ )
{
if ( i3 > 2 )
{
c3 = i3;
s3 = c3;
}
for ( i4 = 1; i4 < 126; i4++ )
{
if ( i4 > 2 )
{
c4 = i4;
s4 = c4;
}
for ( i5 = 1; i5 < 126; i5++ )
{
if ( i5 > 2 )
{
c5 = i5;
s5 = c5;
}
for ( i6 = 1; i6 < 126; i6++ )
{
if ( i6 > 2 )
{
c6 = i6;
s6 = c6;
}
for ( i7 = 1; i7 < 126; i7++ )
{
if ( i7 > 2 )
{
c7 = i7;
s7 = c7;
}
for ( i8 = 1; i8 < 126; i8++ )
{
if ( i8 > 2 )
{
c8 = i8;
s8 = c8;
}
for ( i9 = 1; i9 < 126; i9++ )
{
if ( i9 > 2 )
{
c9 = i9;
s9 = c9;
}
for ( i10 = 1; i10 < 126; i10++ )
{
if ( i10 > 2 )
{
c10 = i10;
s10 = c10;
}
for ( i11 = 1; i11 < 126; i11++ )
{
if ( i11 > 2 )
{
c11 = i11;
s11 = c11;
}
for ( i12 = 1; i12 < 126; i12++ )
{
if ( i12 > 2 )
{
c12 = i12;
s12 = c12;
}
for ( i13 = 1; i13 < 126; i13++ )
{
if ( i13 > 2 )
{
c13 = i13;
s13 = c13;
}
for ( i14 = 1; i14 < 126; i14++ )
{
if ( i14 > 2 )
{
c14 = i14;
s14 = c14;
}
for ( i15 = 1; i15 < 126; i15++ )
{
if ( i15 > 2 )
{
c15 = i15;
s15 = c15;
}
for ( i16 = 1; i16 < 126; i16++ )
{
if ( i16 > 2 )
{
c16 = i16;
s16 = c16;
}
for ( i17 = 1; i17 < 126; i17++ )
{
if ( i17 > 2 )
{
c17 = i17;
s17 = c17;
}
for ( i18 = 1; i18 < 126; i18++ )
{
if ( i18 > 2 )
{
c18 = i18;
s18 = c18;
}
for ( i19 = 1; i19 < 126; i19++ )
{
if ( i19 > 2 )
{
c19 = i19;
s19 = c19;
}
for ( i20 = 1; i20 < 126; i20++ )
{
c20 = i20;
s20 = c20;
ss = s1 + s2 + s3 + s4 + s5 + s6 + s7 + s8 + s9 + s10 + s11 + s12 + s13 + s14 + s15 + s16 + s17 + s18 + s19 + s20;
if ( ss != password )
{
cout << ss << " : Access denied." << endl;
}
else
{
cout << ss << " : Access granted." << endl;
exit(0);
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
int main()
{
//Type in a password.
string password = get_password();
//Trying to get your password.
guess(password);
}
答案 0 :(得分：0)
您正在打印不可打印的字符。具体来说，你的循环生成ASCII值低于32的字符，其中包括BEL字符，这些字符在“打印”时会发出蜂鸣声。
在程序终止后它一直发出哔哔声的原因很可能是缓冲了你的控制台：你的程序生成的输出比控制台可以显示的速度快，所以输出被写入缓冲区并从那里打印出来;一旦你的程序完成，缓冲区仍然需要打印出来。