Problem in making some programs in c++

1. Write a program that inputs a 6- digit positive integer (i.e. in the range 100,000-999,999) and then constructs and output the integer whose digits are the reverseof the input. For example, if 289405 is input, then the integer 504982 is constructed and printed.

2. Write a program that inputs a number of cents( from 0 to 99) and outputs the minimal number of pennies, nickels, dimes, and quarters with the same value. For example, 94 cents is same as 3 quarters, 1 dime, 1 nickel, and 4 pennies.

3. Write a program that asks the user to provide distance in kilometers that you have driven and how many liters of petrol you have used and then report the mileage of your car in liters per 100 kilometers.