public int strStr(String source, String target) {
// Write your code here
if(source==null||target==null||source.length()<target.length())
{
return -1;
}
if(target.length()==0)
{
return 0;
}
int i=0,j=0;
while(i<source.length()&&j<target.length())
{
if(source.charAt(i)==target.charAt(j))
{
i++;
j++;
}
else
{
j=0;
i++;
}
if(j==target.length())
{
return i-target.length();
}
else if(i==source.length())
{
return -1;
}
}
return -1;
}
}
//遇到两个字符串如tartarget和target的时候答案就不对l。