[LeetCode]014-Longest Common Prefix

题目：

Longest Common Prefix

Write a function to find the longest common prefix string amongst an array of strings.

求所有字符串的公共前缀子串

Solution:

string longestCommonPrefix(vector<string>& strs) {
if(strs.size() == 0)
return "";
int length,i,j;
string pre_fix = strs[0];
for(i =1;i<strs.size();i++)
{
string cur_str  = strs[i];
if(pre_fix.size() == 0 || cur_str.size() == 0)
return "";

length = min(cur_str.size(),pre_fix.size());
for(j = 0;j<length;j++)
{
if(cur_str[j] != pre_fix[j])
break;
}
pre_fix = pre_fix.substr(0,j);
}
return pre_fix;
}