lc422-Valid Word Square

Given a sequence of words, check whether it forms a valid word square.

A sequence of words forms a valid word square if the kth row and column read the exact same string, where 0 ≤ k < max(numRows, numColumns).

Note:
The number of words given is at least 1 and does not exceed 500.
Word length will be at least 1 and does not exceed 500.
Each word contains only lowercase English alphabet a-z.

我有不审题和自动脑补题意的坏习惯，一开始以为输入就是一个square..= =

class Solution {
public:
    bool validWordSquare(vector<string>& words) {
        int m = words.size();
        for (int i = 0; i < m; i++) {
            int len = words[i].length();
            if (len > m) return false;
            for (int j = 0; j < len; j++) {
                if (words[j].length() < i+1 || words[j][i] != words[i][j])
                    return false;
            }
        }
        return true;
    }
};