leetcode 240. 搜索二维矩阵 II

2023.11.22

        本题最先想到的是暴力法和二分法，暴力法就不写了，写一下二分法的解法，java代码如下：

class Solution {public boolean searchMatrix(int[][] matrix, int target) {for(int[] row : matrix){int left = 0;int right = row.length-1;while(left <= right){int mid = (left + right) / 2;if(row[mid] == target) return true;else if(row[mid] > target) right = mid-1;else left = mid + 1; }}return false;}
}

        翻看了下评论区，有个Z字型解法，是从右上角开始遍历，我则从左下角开始遍历，然后当前元素大于target值就往上走，小于target值就往右走，直到走到边界也没找到就返回false，java代码如下：

class Solution {public boolean searchMatrix(int[][] matrix, int target) {int row = matrix.length-1;int col = 0;//从左下角开始搜索while(row>=0 && col<matrix[0].length){if(matrix[row][col] == target) return true;else if(matrix[row][col] > target) row--;else col++;}return false;}
}