【代码随想录算法训练营第37期第二天 | LeetCode977.有序数组的平方、209.长度最小的子数组、59.螺旋矩阵II】

代码随想录算法训练营第37期第二天 | LeetCode977.有序数组的平方、209.长度最小的子数组、59.螺旋矩阵II

一、977.有序数组的平方

解题代码C++：

class Solution {
public:vector<int> sortedSquares(vector<int>& nums) {int len = nums.size();for(int i = 0; i < len; i ++)nums[i] = nums[i] * nums[i];sort(nums.begin(), nums.end());return nums;}
};

题目链接/文章讲解/视频讲解：
https://programmercarl.com/0977.%E6%9C%89%E5%BA%8F%E6%95%B0%E7%BB%84%E7%9A%84%E5%B9%B3%E6%96%B9.html

二、209.长度最小的子数组

解题代码C++：

class Solution {
public:int minSubArrayLen(int target, vector<int>& nums) {int len = nums.size();int sum = 0, k = len + 5;for(int i = 0, j = 0; i < len; i ++){sum += nums[i];while(sum >= target && j <= i){sum -= nums[j];j ++;if(sum < target) k = min(k, i - j + 2);}}if(k == len + 5) return 0;else return k;}
};

题目链接/文章讲解/视频讲解：
https://programmercarl.com/0209.%E9%95%BF%E5%BA%A6%E6%9C%80%E5%B0%8F%E7%9A%84%E5%AD%90%E6%95%B0%E7%BB%84.html

三、59.螺旋矩阵II

解题代码C++：

class Solution {
public:vector<vector<int>> generateMatrix(int n) {int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};vector<vector<int>> res(n, vector<int>(n));for(int k = 1, x = 0, y = 0, d = 0; k <= n * n; k ++){res[x][y] = k;int a = x + dx[d], b = y + dy[d];if(a >= n || a < 0 || b >= n || b < 0 || res[a][b]){d = (d + 1) % 4;a = x + dx[d];b = y + dy[d];}x = a, y = b;}return res;}
};