Move the fork outside any if .

Something like

do {

/* your code here */
} while (condition)

Kilometer should be float as well.

You need to allocate sizeof(MNT) not sizeof(MNTPTR) .

To make it for generic you can read 2 strings , calculate their lenght , allocate sufficient memory using malloc to hold both of them and then call strcat.

One for loop running from 1 to 100 should suffice.

Cannot you use std::string apis ?

rather use C++
overload > < and == functions.

Your question is not clear, what exactly do you require?