【leetcode】1476. Subrectangle Queries

题目如下：

Implement the class SubrectangleQueries which receives a rows x cols rectangle as a matrix of integers in the constructor and supports two methods:

1. updateSubrectangle(int row1, int col1, int row2, int col2, int newValue)

• Updates all values with newValue in the subrectangle whose upper left coordinate is (row1,col1) and bottom right coordinate is (row2,col2).

2. getValue(int row, int col)

• Returns the current value of the coordinate (row,col) from the rectangle. 

Example 1:

Input
["SubrectangleQueries","getValue","updateSubrectangle","getValue","getValue","updateSubrectangle","getValue","getValue"]
[[[[1,2,1],[4,3,4],[3,2,1],[1,1,1]]],[0,2],[0,0,3,2,5],[0,2],[3,1],[3,0,3,2,10],[3,1],[0,2]]
Output
[null,1,null,5,5,null,10,5]
Explanation
SubrectangleQueries subrectangleQueries = new SubrectangleQueries([[1,2,1],[4,3,4],[3,2,1],[1,1,1]]);  
// The initial rectangle (4x3) looks like:
// 1 2 1
// 4 3 4
// 3 2 1
// 1 1 1
subrectangleQueries.getValue(0, 2); // return 1
subrectangleQueries.updateSubrectangle(0, 0, 3, 2, 5);
// After this update the rectangle looks like:
// 5 5 5
// 5 5 5
// 5 5 5
// 5 5 5 
subrectangleQueries.getValue(0, 2); // return 5
subrectangleQueries.getValue(3, 1); // return 5
subrectangleQueries.updateSubrectangle(3, 0, 3, 2, 10);
// After this update the rectangle looks like:
// 5   5   5
// 5   5   5
// 5   5   5
// 10  10  10 
subrectangleQueries.getValue(3, 1); // return 10
subrectangleQueries.getValue(0, 2); // return 5

Example 2:

Input
["SubrectangleQueries","getValue","updateSubrectangle","getValue","getValue","updateSubrectangle","getValue"]
[[[[1,1,1],[2,2,2],[3,3,3]]],[0,0],[0,0,2,2,100],[0,0],[2,2],[1,1,2,2,20],[2,2]]
Output
[null,1,null,100,100,null,20]
Explanation
SubrectangleQueries subrectangleQueries = new SubrectangleQueries([[1,1,1],[2,2,2],[3,3,3]]);
subrectangleQueries.getValue(0, 0); // return 1
subrectangleQueries.updateSubrectangle(0, 0, 2, 2, 100);
subrectangleQueries.getValue(0, 0); // return 100
subrectangleQueries.getValue(2, 2); // return 100
subrectangleQueries.updateSubrectangle(1, 1, 2, 2, 20);
subrectangleQueries.getValue(2, 2); // return 20

Constraints:

• There will be at most 500 operations considering both methods: updateSubrectangle and getValue.
• 1 <= rows, cols <= 100
• rows == rectangle.length
• cols == rectangle[i].length
• 0 <= row1 <= row2 < rows
• 0 <= col1 <= col2 < cols
• 1 <= newValue, rectangle[i][j] <= 10^9
• 0 <= row < rows
• 0 <= col < cols

解题思路：本题的数据量不大，O(n^2)的复杂度完全可行。

代码如下：

class SubrectangleQueries(object):

    def __init__(self, rectangle):
        """
        :type rectangle: List[List[int]]
        """
        self.rec = rectangle

    def updateSubrectangle(self, row1, col1, row2, col2, newValue):
        """
        :type row1: int
        :type col1: int
        :type row2: int
        :type col2: int
        :type newValue: int
        :rtype: None
        """
        for i in range(row1,row2+1):
            for j in range(col1,col2+1):
                self.rec[i][j] = newValue


    def getValue(self, row, col):
        """
        :type row: int
        :type col: int
        :rtype: int
        """
        return self.rec[row][col]