we can ignore the matrix because we can simply convert it to a sorted linear array!

```
class Solution(object):
def searchMatrix(self, matrix, target):
"""
:type matrix: List[List[int]]
:type target: int
:rtype: bool
"""
m = len(matrix)
n = len(matrix[0])
xl = 0
xr = m*n-1
while (True):
xm = (xl+xr)/2
if (matrix[xm/n][xm%n] == target):
return True
if (xl >= xr):
return False
if (matrix[xm/n][xm%n] > target):
xr = xm-1
else:
xl = xm+1
```