2. Function letter_percent that reads a sequence of characters. First '*' will terminate the input and returns the percent of letters in the input sequence. Use function isletter that you wrote to determine whether the char is letter or not. The return value is a DECIMAL value of the percent.
For example, if the input is
Ab56Cd90K8*
The function must return 0.5 (since there are 5 letters and 10 chars
in the input, means there are 50% letters in the input and 50% in decimal
is 0.5). Pay attention that we don't count '*' in total number of chars.
3. Function sum_divisor that accepts one integer parameter num and returns the sum of the PROPER divisors of the parameter num.
4. Function isabundant that accepts one integer parameter and returns 1 if the number is abundant and 0 otherwise. Definition: an abundant number or excessive number is a number for which the sum of PROPER divisors is larger than the number itself. Use functin sum_divisors that you wrote, to find the sum of proper divisors.
Examples:
12 is abundant, since the sum of the proper divisors
is 1+2+3+4+6=16 > 12
20 is abundant, since the sum of the proper divisors is 1+2+4+5+10=22 > 20
6 is NOT abundant, since the sum of proper divisors is 1+2+3 = 6 and it is NOT
larger than 6
10 is not abundant, since the sum of proper divisors
is 1 + 2 + 5 = 8 < 10
5. Function menu that accepts one integer parameter. If the parameter is positive, the function letter_percent will be called, if the parameter is negative, the function will ask user to enter additional integer to test for abundance and the function isabundant will be called, and if parameter is 0 - the error message will be printed.
6. main function reads one integer, actual parameter for function menu, and calls function menu to perform the appropriate task.