/************************************************************************* 
  > File Name: vector_rotate.cpp 
  > Author: SongLee 
 ************************************************************************/ 
#include<iostream> 
#include<string> 
using namespace std; 
 
int main() 
{ 
  string s = "abcdefghijklmn"; 
  cout << "The origin is: " << s << endl; 
  // 左移个数 
  int i; 
  cin >> i; 
  if(i > s.size()) 
  { 
    i = i%s.size(); 
  } 
  // 将前i个元素临时保存 
  string tmp(s, 0, i); 
  // 将剩余的左移i个位置 
  for(int  j=i; j<s.size(); ++j) 
  { 
    s[j-i] = s[j]; 
  } 
  s = s.substr(0, s.size()-i) + tmp; 
  cout << "The result is: "<< s << endl; 
  return 0; 
} 

/************************************************************************* 
  > File Name: vector_rotate_1.cpp 
  > Author: SongLee 
 ************************************************************************/ 
#include<iostream> 
#include<string> 
using namespace std; 
 
void rotateOnce(string &s) 
{ 
  char tmp = s[0]; 
  int i; 
  for(i=1; i<s.size(); ++i) 
  { 
    s[i-1] = s[i]; 
  } 
  s[i-1] = tmp; 
} 
 
int main() 
{ 
  string s = "abcdefghijklmn"; 
  cout << "The origin is: " << s << endl; 
  // 左移个数 
  int i; 
  cin >> i; 
  if(i > s.size()) 
  { 
    i = i%s.size(); 
  } 
  // 调用函数i次 
  while(i--) 
  { 
    rotateOnce(s); 
  } 
  cout << "The result is: "<< s << endl; 
  return 0; 
} 

/************************************************************************* 
  > File Name: vector_rotate_2.cpp 
  > Author: SongLee 
 ************************************************************************/ 
#include<iostream> 
#include<string> 
using namespace std; 
 
// 欧几里德（辗转相除）算法求最大公约数 
int gcd(int i, int j) 
{ 
  while(1) 
  { 
    if(i > j) 
    { 
      i = i%j; 
      if(i == 0) 
      { 
        return j; 
      } 
    } 
    if(j > i) 
    { 
      j = j%i; 
      if(j == 0) 
      { 
        return i; 
      } 
    } 
  } 
} 
 
int main() 
{ 
  string s = "abcdefghijklmn"; 
  cout << "The origin is: "<< s << endl; 
  // 左移个数 
  int i; 
  cin >> i; 
  if(i > s.size()) 
  { 
    i = i%s.size(); 
  } 
  // 移动 
  char tmp; 
  int times = gcd(s.size(), i); 
  for(int j=0; j<times; ++j) 
  { 
    tmp = s[j]; 
    int pre = j; // 记录上一次的位置 
    while(1) 
    { 
      int t = pre+i; 
      if(t >= s.size()) 
        t = t-s.size(); 
      if(t == j) // 直到tmp原来的位置j为止 
        break; 
      s[pre] = s[t]; 
      pre = t; 
    } 
    s[pre] = tmp; 
  } 
  cout << "The result is: "<< s << endl; 
  return 0; 
} 

reverse(0, i-1)  /*cbadefgh*/
reverse(i, n-1) /*cbahgfed*/
reverse(0, n-1) /*defghabc*/

/************************************************************************* 
  > File Name: vector_rotate.cpp 
  > Author: SongLee 
 ************************************************************************/ 
#include<iostream> 
#include<string> 
using namespace std; 
 
void reverse(string &s, int begin, int end) 
{ 
  while(begin < end) 
  { 
    char tmp = s[begin]; 
    s[begin] = s[end]; 
    s[end] = tmp; 
    ++begin; 
    --end; 
  } 
} 
 
int main() 
{ 
  string s = "abcdefghijklmn"; 
  cout << "The origin is: "<< s << endl; 
   
  int i; 
  cin >> i; 
  if(i > s.size()) 
  { 
    i = i%s.size(); 
  } 
 
  reverse(s, 0, i-1); 
  reverse(s, i, s.size()-1); 
  reverse(s, 0, s.size()-1); 
 
  cout << "The result is: "<< s << endl; 
  return 0; 
}