Longest Common Prefix （leetcode 14）

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

寻找所有字符串的公共前缀

思路：1，先找出最短的字符串，最长长度肯定比这个要短，减少循环长度

           2，将公共前缀设置为这个最短字符串。

  3，循环，每找到更短的就更短的行就迭代更新最短路径

#include <iostream>
#include <string>
#include <vector>

using namespace std;

class Solution
{
public:
string longestCommonPrefix(vector<string>& strs)
{

int n = strs.size();

if(n ==0)
{
return "";
}

else if(n==1)
{

return strs[0];

}
int shortlength = strs[0].length();
int shortindex = 0;
for(int i=1; i<n; i++)
{
if(strs[i].length() <shortlength)
{
shortlength = strs[i].length();
shortindex = i;
}
}

if(shortlength ==0)
{
return "";
}
else
{
//char * s = new char[shortlength+1];
string shortS = strs[shortindex];
for(int i=0; i<n; i++)
{

for(int j=0; j<shortlength; j++)
{

if(strs[i][j] != shortS[j])
{

shortlength = j;

}

}

}

return shortS.substr(0,shortlength);

}

}
};

int main()
{
vector<string> s;
s.push_back("C");
s.push_back("C");

//cout<<s.size();
Solution solution;
cout<<solution.longestCommonPrefix(s)<<endl;;

return 0;
}