Sum and Update Queries on 2D Matrix
Given a 2D matrix mat[][] of size NXN with all its elements initialized to 0, the task is to answer Q queries. Each query[i] can be one of the following types: Type 1 [1, x, y, ele]: Update the value of cell(x, y) to val.Type 2 [2, x1, y1 ,x2, y2]: Print the sum of the submatrix (x1, y1) to (x2, y2)