二维数组与一维数组转换

二维数组m行n列，一维数组索引为index row = idx // n ， col = idx % n。

标准二分查找算法

class Solution { public boolean searchMatrix(int[][] matrix, int target) { int m = matrix.length; if (m == 0) return false; int n = matrix[0].length; // 二分查找 int left = 0, right = m * n - 1; int pivotIdx, pivotElement; while (left <= right) { pivotIdx = (left + right) / 2; pivotElement = matrix[pivotIdx / n][pivotIdx % n]; if (target == pivotElement) return true; else { if (target < pivotElement) right = pivotIdx - 1; else left = pivotIdx + 1; } } return false; } }