leetcode 14 Longest Common Prefix
class Solution {
public:
string longestCommonPrefix(vector<string>& strs) {
if (strs.empty()) return "";
for (int j = 0; j < strs[0].size(); ++j) {
for (int i = 0; i < strs.size() - 1; ++i) {
if (j >= strs[i].size() || j >= strs[i + 1].size() || strs[i][j] != strs[i + 1][j]) {
return strs[i].substr(0, j);
}
}
}
return strs[0];
}
};