C++编程之美-结构之法(代码清单3-6)

Int CalculateStringDistance(string strA, int pABegin, int pAEnd,
   string strB, int pBBegin, int pBEnd) 
{
     if(pABegin > pAEnd)
     {
          if(pBBegin > pBEnd)
               return 0; 
          else
               return pBEnd – pBBegin + 1;
     }

     if(pBBegin > pBEnd)
     {
          if(pABegin > pAEnd)
               return 0;
          else
               return pAEnd – pABegin + 1;
     }

     if(strA[pABegin] == strB[pBBegin])
     {
          return CalculateStringDistance(strA, pABegin + 1, pAEnd,
            strB, pBBegin + 1, pBEnd);
     }
     else
     {
          int t1 = CalculateStringDistance(strA, pABegin, pAEnd, strB, 
            pBBegin + 1, pBEnd);
          int t2 = CalculateStringDistance(strA, pABegin + 1, pAEnd, 
            strB,pBBegin, pBEnd);
          int t3 = CalculateStringDistance(strA, pABegin + 1, pAEnd,
            strB,pBBegin + 1, pBEnd);
          return minValue(t1,t2,t3) + 1;
     }
}