Problem 4 Write a complete C++ program that does the following.

1. It asks the user to enter a positive integer.

2. The program reads a value n entered by the user. If the value is not legal, the program terminates.

3. The program prints a table with n lines of output. On output line number x the program should list the numbers from 1 to x together with their sum.

Example, if the user enters 7 for n the program should print the following table.

1 the sum is 1

1 2 the sum is 3

1 2 3 the sum is 6

1 2 3 4 the sum is 10

1 2 3 4 5 the sum is 15

1 2 3 4 5 6 the sum is 21

1 2 3 4 5 6 7 the sum is 28