起點（0,0） +  A10  = （-10,0） +  S20  = (-10,-20) +  W10 = (-10,-10) +  D30 = (20,-10) +  x  = 無效 +  A1A  = 無效 +  B10A11  = 無效 + 一個空 不影響 +  A10 = (10,-10) 

#include<iostream> #include<string> using namespace std;  bool isValid(string s, char &key, int &step){   if (s.size()<2 || s.size()>3)return false;   if (s[0] != 'A' && s[0] != 'D' && s[0] != 'W' && s[0] != 'S')     return false;   key = s[0];   if (s.size() == 2 && s[1] >= '0' && s[1] <= '9'){     step = s[1] - '0';     return true;   }   if (s.size() == 3 && s[1] >= '0' && s[1] <= '9' && s[2] >= '0' && s[2] <= '9'){     step = (s[1] - '0') * 10 + (s[2] - '0');     return true;   }   return false; }   void caculator(string s, int &x, int &y, char key, int step){   switch (key){   case 'A':     x -= step;     break;   case 'D':     x += step;     break;   case 'W':     y += step;     break;   case 'S':     y -= step;     break;   }   return; }  int main(){   string str;   while (cin >> str){     int x = 0;     int y = 0;     int i = 0;     while (i<str.size()){       string temp;       char key;       int step;       while (str[i] != ';'){         temp.push_back(str[i]);         i++;       }       if (isValid(temp, key, step))         caculator(temp, x, y, key, step);       i++;     }     cout << x << ',' << y<<endl; //must add endl(wtf...,waste time)   }   return 0; }