### PROBLEM LINK:

**Author:** Arkapravo Ghosh

**Tester:** Arkapravo Ghosh

**Editorialist:** Arkapravo Ghosh

### DIFFICULTY:

EASY

### PREREQUISITES:

2-D ARRAY

### PROBLEM:

We are given a **N x M** matrix. There are two types of queries - **0** and **1**. For the queries of type **0** we need to update the value at a given index to a given value. For the queries of type **1** we need to print the sum of elements of the matrix in the given range.

### EXPLANATION:

For the queries of type **0**, you just need to update the value at the given index to the given value. For the given values of indices **x** and **y** and a value **val** :-

a[x][y] = val

For the queries of type **1**, you need to answer the queries. You are given **4** indices **x1**, **y1**, **x2** and **y2**. You need to print the sum of all the elements between the bounds of **(x1, y1)** and **(x2, y2)**. Simply run two loops for the given bounds and add up the elements. The pseudocode will look somewhat like this :-

sum = 0

for(i = x1; i <= x2; i++)

for(j = y1; j <= y2; j++)

sum := sum + a[i][j]

print(sum)

In programming languages like C, C++ you need to declare sum as a long long int, otherwise it will overflow.

You can find the authors solution below.

### AUTHOR’S AND EDITORIALIST’S SOLUTIONS:

Author’s and editorialist’s solution can be found here.