字符串穷举算法(STL)

这里实现的功能是给出一个任意序列的字符串组合，程序会产生包含所有字符的组合，算法部分用到了C++ STL中的next_permutation()函数，并计算耗时(用到了Win32 API)。代码很简单，就不加注释了....

#include <iostream>
#include <string>
#include <algorithm>
#include <windows.h>
 using namespace std;

 int main()
{
    string letters;
    cout<<">>>>> Enter the STRING to TEST: (quit to quit):";
    
    while (cin>>letters && letters!="quit")
    {
          SYSTEMTIME _time1,_time2; 
          float interval; 
          GetLocalTime(&_time1); 
          
          cout<<"Permutations of"<<letters<<endl;
          sort(letters.begin(),letters.end());
          cout<<letters<<endl;
          double count=1;
          
          while(next_permutation(letters.begin(),letters.end()))
          {
             cout<<letters<<endl;
             ++count;
          }
          
          cout<<">>>>> The aumount:"<<count<<endl;
          cout<<endl;
          
          GetLocalTime(&_time2); 
          interval=(_time2.wMinute-_time1.wMinute)*60; 
          interval+=_time2.wSecond-_time1.wSecond;
          interval*=1000;
          interval+=(_time2.wMilliseconds-_time1.wMilliseconds);
          interval/=1000;
          
          printf(">>>>>耗时: %f 秒\n",interval );
          cout<<endl; 
          cout<<">>>>> Enter next STRING to TEST (quit to quit):";
    }
    system("pause");
    return 0;
}
 

当输入12345678 程序运行效果如下：