problem:
Write a function to find the longest common prefix string amongst an array of strings.
thinking:
(1)公共前綴很好理解,按位匹配即可
(2)很容易忘記處理0、1個字符串的情況。
code:
string prefix(string &str1, string &str2)
{
string tmp;
int i=0;
while((i &strs) {
if(strs.size()==0)
return "";
if(strs.size()==1)
return strs.at(0);
string result=prefix(strs.at(0),strs.at(1));
for(int i=1;i