#include<stdio.h>

int main()
{
char ch;
printf("Enter Your State Name : ");
scanf("%c",&ch);

if(ch == 'a')
printf("Shipping Charge : $25");

else if(ch == 'b')
printf("Shipping Charge : $50");
else if(ch == 'c')
printf("Shipping Charge : $65");

else
printf("The state not in purchase");

return 0;
}

This program is written in the C programming language and calculates the shipping charge based on the user's input.

1. First, it includes the `stdio.h` header file which is required for input and output functions.
2. The `main()` function is the entry point of the program.
3. It declares a variable `ch` of type `char` to store the user input for state name.
4. It then prompts the user to enter their state name using the `printf()` function.
5. The `scanf()` function is used to read a character from the user and store it in the variable `ch`.
6. The program then uses an `if-else` ladder to check the value of `ch` and determine the shipping charge for the corresponding state.
7. If the state name is 'a', it will print "Shipping Charge : $25".
8. If the state name is 'b', it will print "Shipping Charge : $50".
9. If the state name is 'c', it will print "Shipping Charge : $65".
10. If the state name is none of the above, it will print "The state not in purchase".
11. Finally, the `return 0` statement signifies the end of the `main()` function and the program.

To run this program, you will need a C compiler such as GCC. After compiling, the program will prompt you to enter a state name, and it will display the corresponding shipping charge based on the input.