[leetCode刷题笔记]2017.04.17

原创于 2017-04-17 22:04:44 发布 · 700 阅读

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本文介绍了解决两个经典算法问题的方法：构造面积给定的最小差值矩形和寻找两字符串间的最长不同子序列。对于矩形构造问题，通过寻找接近平方根的因数来获得最佳长宽比；而不同子序列问题，则直接比较两个字符串并返回最长的一个。

492. Construct the Rectangle

class Solution(object):
    def constructRectangle(self, area):
        """
        :type area: int
        :rtype: List[int]
        """
        mid = int(math.sqrt(area))
        while mid > 0:
            if area % mid == 0:
                return [int(area / mid), int(mid)]
            mid -= 1

521. Longest Uncommon Subsequence I

class Solution(object):
    def findLUSlength(self, a, b):
        """
        :type a: str
        :type b: str
        :rtype: int
        """
        if a == b:
            return -1
        return max(len(a), len(b))

530. Minimum Absolute Difference in BST

public class Solution {
    int min = Integer.MAX_VALUE;
    Integer prev = null;
    
    public int getMinimumDifference(TreeNode root) {
        if (root == null) return min;
        
        getMinimumDifference(root.left);
        
        if (prev != null) {
            min = Math.min(min, root.val - prev);
        }
        prev = root.val;
        
        getMinimumDifference(root.right);
        
        return min;
    }
}