题目描述：
请你实现一个类 SubrectangleQueries ，它的构造函数的参数是一个 rows x cols 的矩形（这里用整数矩阵表示），并支持以下两种操作：
- updateSubrectangle(int row1, int col1, int row2, int col2, int newValue)
用 newValue 更新以 (row1,col1) 为左上角且以 (row2,col2) 为右下角的子矩形。 - getValue(int row, int col)
返回矩形中坐标 (row,col) 的当前值
示例 1：
输入：
[“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]]
输出：
[null,1,null,5,5,null,10,5]
解释：
SubrectangleQueries subrectangleQueries = new SubrectangleQueries([[1,2,1],[4,3,4],[3,2,1],[1,1,1]]);
// 初始的 (4x3) 矩形如下：
// 1 2 1
// 4 3 4
// 3 2 1
// 1 1 1
subrectangleQueries.getValue(0, 2); // 返回 1
subrectangleQueries.updateSubrectangle(0, 0, 3, 2, 5);
// 此次更新后矩形变为：
// 5 5 5
// 5 5 5
// 5 5 5
// 5 5 5
subrectangleQueries.getValue(0, 2); // 返回 5
subrectangleQueries.getValue(3, 1); // 返回 5
subrectangleQueries.updateSubrectangle(3, 0, 3, 2, 10);
// 此次更新后矩形变为：
// 5 5 5
// 5 5 5
// 5 5 5
// 10 10 10
subrectangleQueries.getValue(3, 1); // 返回 10
subrectangleQueries.getValue(0, 2); // 返回 5
示例 2：
输入：
[“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]]
输出：
[null,1,null,100,100,null,20]
解释：
SubrectangleQueries subrectangleQueries = new SubrectangleQueries([[1,1,1],[2,2,2],[3,3,3]]);
subrectangleQueries.getValue(0, 0); // 返回 1
subrectangleQueries.updateSubrectangle(0, 0, 2, 2, 100);
subrectangleQueries.getValue(0, 0); // 返回 100
subrectangleQueries.getValue(2, 2); // 返回 100
subrectangleQueries.updateSubrectangle(1, 1, 2, 2, 20);
subrectangleQueries.getValue(2, 2); // 返回 20
提示：
最多有 500 次updateSubrectangle 和 getValue 操作。
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
方法1：
主要思路：解题链接汇总
（1）将改变过的区域记录下来，然后在获取某个位置的值时，先对该记录从后向前遍历，若是当前位置在某个记录所在的区域内，则返回当前记录中的值，否则返回原始数组中该位置的值；
class SubrectangleQueries {
public:
vector<vector<int>> rec;
vector<vector<int>> changes;//改变的记录
SubrectangleQueries(vector<vector<int>>& rectangle):rec(rectangle) {
}
void updateSubrectangle(int row1, int col1, int row2, int col2, int newValue) {
changes.push_back({
row1,col1,row2,col2,newValue});
}
int getValue(int row, int col) {
for(int i=changes.size()-1;i>=0;--i){
//该位置是否在某个记录所对应的区域
if(row>=changes[i][0]&&col>=changes[i][1]&&row<=changes[i][2]&&col<=changes[i][3]){
return changes[i][4];
}
}
return rec[row][col];
}
};
/**
* Your SubrectangleQueries object will be instantiated and called as such:
* SubrectangleQueries* obj = new SubrectangleQueries(rectangle);
* obj->updateSubrectangle(row1,col1,row2,col2,newValue);
* int param_2 = obj->getValue(row,col);
*/
//方法1使用go语言实现
type SubrectangleQueries struct {
rec [][]int
change [][]int
}
func Constructor(rectangle [][]int) SubrectangleQueries {
return SubrectangleQueries{
rec:rectangle,
change:[][]int{
},
}
}
func (this *SubrectangleQueries) UpdateSubrectangle(row1 int, col1 int, row2 int, col2 int, newValue int) {
this.change=append(this.change,[]int{
row1,col1,row2,col2,newValue})
}
func (this *SubrectangleQueries) GetValue(row int, col int) int {
for i := len(this.change)-1;i>=0;i--{
if this.change[i][0]<=row&&this.change[i][1]<=col&&
this.change[i][2]>=row&&this.change[i][3]>=col {
return this.change[i][4]
}
}
return this.rec[row][col]
}
/**
* Your SubrectangleQueries object will be instantiated and called as such:
* obj := Constructor(rectangle);
* obj.UpdateSubrectangle(row1,col1,row2,col2,newValue);
* param_2 := obj.GetValue(row,col);
*/
方法2：
主要思路：
（1）直接模拟修改过程即可；
class SubrectangleQueries {
public:
vector<vector<int>> rec;
SubrectangleQueries(vector<vector<int>>& rectangle):rec(rectangle) {
}
void updateSubrectangle(int row1, int col1, int row2, int col2, int newValue) {
for(int i=row1;i<=row2;++i){
for(int j=col1;j<=col2;++j){
rec[i][j]=newValue;
}
}
}
int getValue(int row, int col) {
return rec[row][col];
}
};
/**
* Your SubrectangleQueries object will be instantiated and called as such:
* SubrectangleQueries* obj = new SubrectangleQueries(rectangle);
* obj->updateSubrectangle(row1,col1,row2,col2,newValue);
* int param_2 = obj->getValue(row,col);
*/
//对应的go实现
type SubrectangleQueries struct {
rec [][]int
}
func Constructor(rectangle [][]int) SubrectangleQueries {
return SubrectangleQueries{
rec:rectangle,
}
}
func (this *SubrectangleQueries) UpdateSubrectangle(row1 int, col1 int, row2 int, col2 int, newValue int) {
for i:=row1;i<=row2;i++ {
for j:=col1;j<=col2;j++{
this.rec[i][j]=newValue
}
}
}
func (this *SubrectangleQueries) GetValue(row int, col int) int {
return this.rec[row][col]
}
/**
* Your SubrectangleQueries object will be instantiated and called as such:
* obj := Constructor(rectangle);
* obj.UpdateSubrectangle(row1,col1,row2,col2,newValue);
* param_2 := obj.GetValue(row,col);
*/