LeetCode-Longest Common Prefix

class Solution {
public:
string longestCommonPrefix(vector<string> &strs) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
string prefix;
vector<string>::iterator iter;
string::size_type maxLen = 0;
for (iter = strs.begin(); iter != strs.end(); ++iter)
{
maxLen = max((*iter).size(), maxLen);
}
string::size_type i = 0;
for (; i < maxLen; ++i)
{
char c;
for (iter = strs.begin(); iter != strs.end(); ++iter)
{
if (iter == strs.begin())
{
c = (*iter)[i];
}
else if (c != (*iter)[i])
{
break;
}
}
if (iter != strs.end())
{
break;
}
}
prefix = strs.size() != 0 ? strs[0].substr(0, i) : prefix;
return prefix;
}
};