Leetcode – Longest Common Prefix

Name: Longest Common Prefix
Difficulty: Easy
Description: Find the longest common prefix amongst several words


Given ["flower", "flow", "flight"], return "fl"
Given ["car", "tree"], return ""
Given ["c"] return "c"

I was pretty tired when coding this one, time for bed 🙂

string longestCommonPrefix(vector<string>& strs) {
    const string& word = strs[0];

    if (strs.size() == 1) return word;

    for (auto i = 0; i < word.size(); ++i) {
        for (auto j = 1; j < strs.size(); ++j) {
            if (strs[j][i] != word[i]) {
                return i > 0 ? word.substr(0, i) : "";

    return word;

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