14. Longest Common Prefix

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 “”.

• Time : O(k * min(length of str))
• Space : O(1)

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        int index = 0, target, find = 1;
        for(; find ; index++) {
            for(target = 0; target <= strs.size(); target++) {
                if(strs[target].length() == index) {find = 0; break;}
                if(strs[target][index] != strs[0][index]) {find = 0; break;}
            }
        }
        return strs[target].substr(0,index-1);
    }
};