我的VC ++ 2008似乎有缺陷 [英] My VC++ 2008 Seems Flawed

问题描述

我的VC ++ 2008出现了某些问题，因为执行以下功能将花费超过10分钟的时间.特别令人感兴趣的是擦除方法，该方法可在将近200万个项目上运行近10分钟.谁能发现问题?


避免CrippleTheCpu()

{

Something isn't right about my VC++ 2008 as the following function will take more than 10 minutes to execute.  Of particular interest is the erase method that runs for nearly 10 minutes on a little more than 2 million items.  Can anyone spot the problem?


void CrippleTheCpu()

{

字符 b [64];

char b[64];

 

int ii;

int ii;

 

int jj;

向量<字符串> vs;

int jj;

vector < string > vs;

(jj = 0; jj< 2200000; jj ++)

{

for (jj = 0; jj < 2200000; jj++)

{

(ii = 0; ii< 48; ii ++)

b [ii] =

for (ii = 0; ii < 48; ii++)

b[ii] =

"0" + rand()％32;

b [ii] =

'0' + rand() % 32;

b[ii] =

'\ 0' ;

vs.push_back(b);

'\0';

vs.push_back(b);

}

vs.erase(vs.begin()，vs.end()); //这行将花费近10分钟的时间执行?！?！

返回 ;

}

谢谢

return;

}

Thank you,

推荐答案

我的VC ++ 2008出现了某些问题

b [ii] =

Something isn't right about my VC++ 2008

for (ii = 0; ii < 48; ii++)

b[ii] =

+ rand ()％32;

b [ii] =

'0' + rand() % 32;

b[ii] =

;

'\0';

如果要擦除整个矢量，请使用vs.clear()方法.

您正在使用 vs.erase(vs .begin()，vs.end());

基本上是什么擦除 [迭代器擦除( 迭代器 _First ， 迭代器 _Last )； ] 是，它将删除给定范围内的元素并交换元素(重新排列).对流用于删除一定范围内的元素.

您知道要在字符数组 b 中插入什么吗?每次都是'\ 0'(请参见引用的)

 If you want to erase the entire vector use vs.clear() method.

You are uisng  vs.erase(vs.begin(), vs.end()); 

Basically what erase [iterator erase(iterator _First, iterator _Last); ] does is, it removes the elements in the given range and swaping the elements (rearranging). It is given for a convection to delete the elements in a certain range.

Do you know what are you inserting to the character array b? Everytime it is '\0' (See the quoted)

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