題目地址:
https://leetcode.com/problems/valid-word-square/
給定一個字符串列表,判斷一下其作爲字符二維矩陣是否關於從左上到右下的對角線對稱。可以將每列的字符串求出來,然後和對應行的字符串進行比較。代碼如下:
class Solution {
public boolean validWordSquare(List<String> words) {
if (words == null || words.isEmpty()) {
return true;
}
StringBuilder sb = new StringBuilder();
int n = words.get(0).length();
for (int i = 0; i < n; i++) {
sb.setLength(0);
for (int j = 0; j < words.size(); j++) {
if (i < words.get(j).length()) {
sb.append(words.get(j).charAt(i));
} else {
break;
}
}
if (!sb.toString().equals(words.get(i))) {
return false;
}
}
return true;
}
}
時間複雜度,空間複雜度,爲行數,爲列數。