在一個字符串中查找某一個子串

寫一個函數 BOOL Grep(char *strRef, char *strSub);實現如下功能

判斷一個字符串 strRef 裏面是否存在這樣一個子串 strSub:

1.strSub是strRef的起始子串。或是
2.strSub的前一個字符不是0-9,a-z,A-Z中的任何一個字符。

比如：
1.strSub = "jalan"
  strRef = "jalan dusan"

  Grep(strRef1, strSub)返回true;

2.strSub = "jalan"
  strRef = "Bajalan dusan"

  Grep(strRef1, strSub)返回false;

3.strSub = "jalan"
  strRef = "Bajalan dusan, jalan pemimpin"

  Grep(strRef, strSub)返回true;

 

 Zbool NFSearch::Grep(const Zint8* strRef, const Zint8* strSub) { if(strRef == NULL || strSub == NULL){ return Z_FALSE; } string strSrc(strRef); string strDes(strSub); strSrc = " " + strSrc;// pad a space charecter ahead. Zint32 nFound = strSrc.find(strDes); while(nFound != string::npos){ if(nFound == 0){ return Z_TRUE; } else{ if(((strSrc[nFound-1] >= '0') && (strSrc[nFound-1] <= '9')) ||(strSrc[nFound-1] >= 'A') && (strSrc[nFound-1] <= 'Z') ||((strSrc[nFound-1] >= 'a') && (strSrc[nFound-1] <= 'z'))){ nFound = strSrc.find(strDes, nFound+1); continue; } else{ return Z_TRUE; } } } return Z_FALSE; }