Question

当我调用sort数组函数时，这个程序运行得非常慢。如果我在排序之前打印出数组的元素，它会在几秒钟内运行。如果没有，有时需要一分钟来运行一个非常短的文本文件。这个程序的第一个命令行参数是一本＆＃34;书＆＃34; （包含全部小写字的文本文件）和第二个命令行参数（x）表示最常出现的x个字出现的次数。任何有关如何快速排序结构数组的帮助都会非常有用！

using namespace std;

//void insertionSort(struct count array[],int size);
void sortArray(struct count array[], int size);
bool ExcludeCommon(string word);


struct count
{
string word;
int frequency;
};

int main(int argc, char *argv[])
{
ifstream filename;
filename.open(argv[1]);
ifstream num_words;

int num = stoi((argv[2]));

string one_word;
int size = 100;
count *count_array = new count[size];
int total_non_comm=0;
int words_in_arr = 0;
int double_count=0;
while (filename >> one_word)
{   
    int i;
    int freq = 1;
    bool found = false;

    if(ExcludeCommon(one_word)==0)
    {
        if(total_non_comm>=size)
            {
                count *new2= new count[size*2];
                for(int i=0; i<size; i++)
                    {
                        new2[i]=count_array[i];
                        }
                size = size*2;
                delete[] count_array;
                count_array=new2;
                double_count++;

            }

        for(i=0; i<=words_in_arr; i++)
        {

                if(count_array[i].word == one_word)
                {
                count_array[i].frequency++;
                found=true;
                total_non_comm++;
                }

        }
        if(found == false)
        {
            struct count add;
            add.word = one_word;
            add.frequency = freq++;
            count_array[words_in_arr]=add;
            words_in_arr++;
            total_non_comm++;
        }

        found = false;

    }

}

 sortArray(count_array, size);

for(int i=0; i<num;i++)
{
cout<<count_array[i].frequency<< " - " << count_array[i].word<<endl;
}
cout<<"#"<<endl;
cout<<"Array doubled: "<<double_count-3<<endl;
cout<<"#"<<endl;
cout<<"Unique non-common words: " <<words_in_arr<<endl;
cout<<"#"<<endl;
cout<<"Total non-common words: " << total_non_comm <<endl;



};








bool ExcludeCommon(string word)
{
    if (word == "the" || word == "be" || word == "to" || word == "of" || 
word == "and" || word == "a" || word == "in" || word == "that" || 
word == "have" ||word == "i" || word == "it" || word == "for" || word == "not" || 
word == "on" || word == "with" || word == "he" || word == "as" || 
word == "you" || word == "do" || word == "at" || word == "this" || 
word == "but" || word == "his" || word == "by" || word == "from"||
word == "they" || word == "we" || word == "say" || word == "her" || 
word == "she" || word == "or" || word == "an" || word == "will" || 
word == "my" || word == "one" || word == "all" || word == "would" || 
word == "there" || word == "their" || word == "what" || word == "so" || 
word == "up" || word == "out" || word == "if" || word == "about" || 
word == "who" || word == "get" || word == "which" ||word == "go" || word == "me")

{return 1;
}
return 0;
};


void sortArray(struct count array[],int size)
{
int cur_pos = 0;
string the_word;


   for(int i=0; i<(size); i++)
{
    for(int j=size-1; j>=i; j--)
    {
        if((array[j+1].frequency)>(array[j].frequency))
        {
            cur_pos = array[j].frequency;
            the_word = array[j].word;
            array[j].frequency = array[j+1].frequency;
            array[j].word = array[j+1].word;
            array[j+1].frequency = cur_pos;
            array[j+1].word = the_word;


        }
    }
}

};

Answer 1

您有一个struct count，然后您还有using namespace std;。您是否意识到有std::count？

尽量不要使用

using namespace std;

另外，将struct count更改为struct Count。

出现排序功能问题，您可以使用std::sort实现它。

struct CountCompare
{
   bool operator()(Count const& lhs, Count const& rhs)
   {
      return  (lhs.frequency < rhs.frequency);
   }
};

void sortArray(struct Count array[],int size)
{
   std::sort(array, array+size, CountCompare());
};

这应该比你拥有的要快得多（N.logN vs N ^ 2）。

更快的方式来运行这个简单的c ++程序（排序数组的结构）

1 个答案: