Answer in c++

Write program neatly and simply

1. Write a program asking the user to enter a positive number. Validate the input. Using a for loop, print the sequence of numbers from 1 through the user's number, but print negative values for even numbers. Sample run of program: Enter a number positive number: > -4 Invalid input! Enter a positive number: > 7 1 -2 3-4 5 6 7