Day2 | 209.长度最小的子数组 | 59.螺旋矩阵II

209. 长度最小的子数组 - 力扣（LeetCode）

class Solution {
    public int minSubArrayLen(int target, int[] nums) {
        int left = 0;int right = 0;
        int sum = 0;
        int len = Integer.MAX_VALUE;
        while(right<nums.length){
            sum += nums[right];
            while(sum>=target){
                len = len>(right - left +1)?(right - left +1):len; 
                sum -= nums[left++];
            }
             right++;
        }
        return len==Integer.MAX_VALUE?0:len;
    }
}

59. 螺旋矩阵 II - 力扣（LeetCode）

版本一，最后一边有问题。

class Solution {
    public int[][] generateMatrix(int n) {
        int[][] nums = new int[n][n];
        int startX = 0, startY = 0, offset = 0, count = 1;
        while (offset < n / 2) {
            for (int i = startX; i < n - 1 - offset; i++) {
                nums[startY][i] = count++;
            }

            for (int i = startY; i < n - 1 - offset; i++) {
                nums[i][n - 1 - offset] = count;
                count++;
            }
            startY++;
            
            for (int i = n - 1 - offset; i >0; i--) {
                nums[n - 1 - offset][i] = count;
                count++;
            }

            for (int i = n - 1 - offset; i > 0; i--) {
                nums[i][startX] = count;
                count++;

            }
            startX++;
            offset++;
        }
        if (n % 2 != 0) {
            nums[n / 2][n / 2] = count;
        }
        return nums;
    }
}

版本二，GPT给的。

class Solution {
    public int[][] generateMatrix(int n) {
        int[][] nums = new int[n][n];
        int startX = 0, startY = 0, endX = n - 1, endY = n - 1, count = 1;
        
        while (startX <= endX && startY <= endY) {
            for (int i = startY; i <= endY; i++) {
                nums[startX][i] = count++;
            }
            startX++;
            
            for (int i = startX; i <= endX; i++) {
                nums[i][endY] = count++;
            }
            endY--;
            
            if (startX <= endX) {
                for (int i = endY; i >= startY; i--) {
                    nums[endX][i] = count++;
                }
                endX--;
            }
            
            if (startY <= endY) {
                for (int i = endX; i >= startX; i--) {
                    nums[i][startY] = count++;
                }
                startY++;
            }
        }
        
        return nums;
    }
}

属于是螺旋矩阵没螺明白。