977.有序数组的平方
问题
Given an integer array
numssorted in non-decreasing order, return an array of the squares of each number sorted in non-decreasing order.
LC链接
leetcode.com/problems/sq…
文章讲解
programmercarl.com/0977.%E6%9C…
注意点
Two pointers, 因为平方后的值是向内递减.
209.长度最小的子数组
问题
Given an array of positive integers
numsand a positive integertarget, return the minimal length of a subarray whose sum is greater than or equal totarget. If there is no such subarray, return0instead.
LC链接
leetcode.com/problems/mi…
文章讲解
programmercarl.com/0209.%E9%95…
注意点
Sliding window, 同two pointers类似.
两层循环可以看成滑动窗口的冗余版, 每次窗口前沿移动时, 后沿都需要从前沿开始遍历, 删掉这部分冗余即可.
59.螺旋矩阵II
模拟题, 需关注边界范围(开和闭), 以及保持模拟循环不变量.
