Can someone please help me where to begin on this problem... I don't want answers, just some guidance:

I have to make a program that reads a 4 digit integer: and encrypt it with a calculation: then swap 1st digit with 3rd, swap 2nd digit with 4th and print the integer; then write another program that inputs the encrypted 4 digit int and decrypt from the original number.

I want to use rand() and srand() to generate the numbers. But, I am also considering an array and create constant numbers to input: I thought that by scrammbling the numbers on input that this would automatically encrypt the numbers... (?): I am confused on where to begin to solve this problem (I do understand the calculation but am stuck on the encryption and decryption issue). Also, I think this problem needs to use a nested approach.... please tell me if I am on the right track: or can you please give me some direction or tell me if I am thinking correctly! I just need some clarity... thank you.

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