编程珠玑--左旋字符串

 1 #include <iostream>
 2 #include <string>
 3 
 4 using namespace std;
 5 
 6 void reverseStr(string &s,int i,int j)
 7 {
 8     while(i < j)
 9     {
10         char tmp = s[i];
11         s[i] = s[j];
12         s[j] = tmp;
13         ++i;
14         --j;
15     }
16 }
17 
18 void leftRotate(string &s,int k)
19 {
20     int len = s.length();
21     k = k%len;
22     reverseStr(s,0,k-1);
23     reverseStr(s,k,len-1);
24     reverseStr(s,0,len-1);
25 }
26 
27 int main()
28 {
29     string s("abcdefgh");
30     leftRotate(s,3);
31     cout<<s<<endl;
32     return 0;
33 }