LeetCode-13 羅馬數字轉整數

• C++

  class Solution {
  public:
      int romanToInt(string s) {
          int length = s.length();
          int res = 0;
          for(int i=0;i<length;i++){
              if(s[i]=='M'){
                  res += 1000;
              }else if(s[i]=='C'){
                  if((i+1)<length){
                      if(s[i+1]=='D'){
                          res += 400;
                          i++;
                      }else if(s[i+1]=='M'){
                          res += 900;
                          i++;
                      }else{
                          res += 100;
                      }
                  }else{
                      res += 100;
                  }
              }else if(s[i]=='D'){
                  res += 500;
              }else if(s[i]=='X'){
                  if((i+1)<length){
                      if(s[i+1]=='L'){
                          res += 40;
                          i++;
                      }else if(s[i+1]=='C'){
                          res += 90;
                          i++;
                      }else{
                          res += 10;
                      }
                  }else{
                      res += 10;
                  }
              }else if(s[i]=='L'){
                  res += 50;
              }else if(s[i]=='I'){
                  if((i+1)<length){
                      if(s[i+1]=='V'){
                          res += 4;
                          i++;
                      }else if(s[i+1]=='X'){
                          res += 9;
                          i++;
                      }else{
                          res += 1;
                      }
                  }else{
                      res += 1;
                  }
              }else{
                  res += 5;
              }
          }
          return res;
      }
  };