« back

Longest Common Prefix

Tags : string, leetcode, cpp, easy

Problem Statement - link #

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

If there is no common prefix, return an empty string “”.

Examples #

Example 1:

Input: strs = ["flower","flow","flight"]
Output: "fl"

Example 2:

Input: strs = ["dog","racecar","car"]
Output: ""
Explanation: There is no common prefix among the input strings.

Constraints #

Solutions #

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
      string res = "";
      if(strs[0]=="") return "";
      char t;
      for(int j=0; j<strs[0].size(); j++){
        t=strs[0][j];
        for(int i=1; i<strs.size(); i++){
          if(j >= strs[i].size() or t!=strs[i][j])
            return res;
        }       
        res += t;
      }

      return res;
    }
};