####这是个递归全排列的输出问题，
从集合里只有一个元素开始，每次添加一个元素，插入到上个集合每一个元素的每一个位置。共N！输出
1 elements: a
2 elements: ab ba
3 elements: abc acb cab bac bca cba
1 #include <stdio.h>
2 #include <iostram>
3 #include <algrothm>
4 using namespace std;
5
6 void writeln(string &str)
7 {
8 cout << "writelen(" << str[0];
9 for ( int i = 1 ; i < str.size(); i++ ){
10 cout << "," << str[i];
11 }
12 cout << ")" << endl;
13 }
14
15 void mateloop_sort(int start, int end , string &str)
16 {
17 if (start == end){
18 writeln(str);
19 return;
20 }
21 for ( int i = 0 ; i < str.size() ; i++){
22 cout << "if " << str[start-1] << " < " << str[start] << " then" << endl;
23 str.insert(i,'a'+i,1);
24 }
25
26
27 count << "else"
28 }
29
30 int main()
31 {
32 int num;
33 int i ;
34 char var[7]={"abcdef"};
35 cout << "program sort(input,output);" << endl;
36 cout << "var" << endl;
37
38 cin >> num;
39 for ( i = 0; i < num-1 ; i++)
40 cout << var[i] << ",";
41 cout << var[i] << " : integer;" << endl;
42 cout << "begin" << endl;
43 cout << "readline(";
44 for ( i = 0 ; i < num -1;i++)
45 cout << var[i] << ",";
46 cout << var[i] << ")" << endl;
47
48 string str("a");
49 mateloop_sort(1,num, str);
50
51 cout << "end" << endl;
52
53 return 0;
54 }