longestCommonPrefix(vector<string>& strs)什么意思

words) function?

The longestCommonPrefix function takes a vector of strings as input and returns a string that is the longest common prefix among all the strings in the vector. The function works by comparing the characters of the strings in the vector starting from the first character and returning the prefix that is common among all the strings.

Here is the code for the longestCommonPrefix function:

string longestCommonPrefix(vector<string>& words) {
    if (words.empty()) return "";
    string prefix = words[0];
    for (int i = 1; i < words.size(); i++) {
        int j = 0;
        while (j < prefix.size() && j < words[i].size() && prefix[j] == words[i][j]) {
            j++;
        }
        prefix = prefix.substr(0, j);
        if (prefix.empty()) return "";
    }
    return prefix;
}

The function first checks if the vector is empty and returns an empty string if it is. It then initializes the prefix string to the first string in the vector. The function then loops through the rest of the strings in the vector, comparing each character of the prefix string with the corresponding character of the current string in the loop. If the characters match, the loop continues to the next character. If the characters do not match, the function updates the prefix string to only include the characters up to and including the last matching character. If the prefix string becomes empty, the function returns an empty string. Once the loop has finished, the function returns the final prefix string that is common among all the strings in the vector.