please help me figure out this problem in c++.

Problem B: Days until summer (20 points) Write a program that lets you enter two dates: a start date and end date. Then find the number of days between them. You may assume only valid dates are entered, but you should account for the case when the start date is after the end date. (Hint: I'd suggest continuing what you have from lab, rather than trying a mathematical approach. Then adding either 3 new functions or 1 call-by-reference function if you did the last part in main().) Example 1 (user input underlined): Enter start date (no spaces): 2/27/2020 Enter end date (no spaces): 5/12/2020 You have to wait 75 days Example 2 (user input underlined): Enter start date (no spaces): 2/28/2020 Enter end date (no spaces): 3/8/2020 You have to wait 9 days Example 3 (user input underlined): Enter start date (no spaces): 1/2/3 Enter end date (no spaces): 3/21/12345 You have to wait 4507901 days Example 4 (user input underlined): Enter start date (no spaces): 1/2/3 Enter end date (no spaces): 3/2/1 Never...