题目
跟剑指中题目相同。

class Solution {public boolean searchMatrix(int[][] matrix, int target) {int m = matrix.length, n = matrix[0].length;int i = m - 1, j = 0;while (i >= 0 && j < n) {if (matrix[i][j] == target) {return true;} else if (matrix[i][j] > target) {--i;} else {++j;}}return false;}
}