出處：https://onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=3143
There is a matrix containing at most 106 elements divided into r rows and c columns. Each element has a location (x, y) where 1 ≤ x ≤ r, 1 ≤ y ≤ c. Initially, all the elements are zero. You need to handle four kinds of operations:
1 x1 y1 x2 y2 v Increment each element (x, y) in submatrix (x1, y1, x2, y2) by v (v >0)
2 x1 y1 x2 y2 v Set each element (x, y) in submatrix (x1, y1, x2, y2) to v
3 x1 y1 x2 y2 Output the summation, min value and max value of submatrix(x1, y1, x2, y2)
In the above descriptions, submatrix (x1, y1, x2, y2) means all the elements (x, y) satisfying x1 ≤x ≤ x2 and y1 ≤ x ≤ y2. It is guaranteed that 1 ≤ x1 ≤ x2 ≤ r, 1 ≤ y1 ≤ y2 ≤ c. After any operation,the sum of all the elements in the matrix does not exceed 10^9
Input
There are several test cases. The first line of each case contains three positive integers r, c, m, where m (1 ≤ m ≤ 20, 000) is the number of operations. Each of the next m lines contains a query. There will be at most twenty rows in the matrix. The input is terminated by end-of-file (EOF).
Output
For each type-3 query, print the summation, min and max.
Sample Input
4 4 8
1 1 2 4 4 5
3 2 1 4 4
1 1 1 3 4 2
3 1 2 4 4
3 1 1 3 4
2 2 1 4 4 2
3 1 2 4 4
1 1 1 4 3 3
Sample Output
45 0 5
78 5 7
69 2 7
39 2 7
解題策略：segment tree
將二維陣列轉換成一維陣列，使用區間方式更改segment tree
參考程式碼