从二维矩阵的左下角开始遍历像二叉搜索树class Solution { public boolean searchMatrix(int[][] matrix, int target) { int i matrix.length - 1; int j 0; while(i 0 j matrix[0].length){ if(matrix[i][j] target){ return true; }else if(matrix[i][j] target){ i--; }else{ j; } } return false; } }class Solution { public boolean searchMatrix(int[][] matrix, int target) { int m matrix.length; int n matrix[0].length; int left 0; int right m * n; while(left right){ int mid left (right - left) / 2; int temp matrix[mid / n][mid % n]; if(temp target){ return true; }else if(temp target){ right mid; }else{ left mid 1; } } return false; } }