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....

 1 #include <iostream>
 2 #include <string>
 3 #include <algorithm>
 4 #include <windows.h>
 5  using namespace std;
 6 
 7  int main()
 8 {
 9     string letters;
10     cout<<">>>>> Enter the STRING to TEST: (quit to quit):";
11     
12     while (cin>>letters && letters!="quit")
13     {
14           SYSTEMTIME _time1,_time2; 
15           float interval; 
16           GetLocalTime(&_time1); 
17           
18           cout<<"Permutations of"<<letters<<endl;
19           sort(letters.begin(),letters.end());
20           cout<<letters<<endl;
21           double count=1;
22           
23           while(next_permutation(letters.begin(),letters.end()))
24           {
25              cout<<letters<<endl;
26              ++count;
27           }
28           
29           cout<<">>>>> The aumount:"<<count<<endl;
30           cout<<endl;
31           
32           GetLocalTime(&_time2); 
33           interval=(_time2.wMinute-_time1.wMinute)*60; 
34           interval+=_time2.wSecond-_time1.wSecond;
35           interval*=1000;
36           interval+=(_time2.wMilliseconds-_time1.wMilliseconds);
37           interval/=1000;
38           
39           printf(">>>>>耗时: %f 秒\n",interval );
40           cout<<endl; 
41           cout<<">>>>> Enter next STRING to TEST (quit to quit):";
42     }
43     system("pause");
44     return 0;
45 }
46

当输入12345678 程序运行效果如下：