Exercise $3.$

Use the program shell below to implement a program called SumDigits. When completed, program

SumDigits prompts for and reads a one$-$digit number, then adds the numbers from zero to the number,

inclusive, and prints the sum.

$//$ Program SumDigits prompts for and reads a one$-$digit number.

$//$ Values between $0$ and the digit $($inclusive$)$ are summed.

#include

using namespace std;

int main $()$

$\{$

int counter; $//$ Loop$-$control variable

int sum; $//$ Running sum

int digit;

cout $<<$ "Enter a one$-$digit number; press return."

$<<$ endl;

cin $>>$ digit;

counter $=/*$ TO BE FILLED IN $*/$

sum $=/*$ TO BE FILLED IN $*/$

while $/*$ TO BE FILLED IN $*/$

$\{$

$/*$ TO BE FILLED IN $*/$

$\}$

cout $<<$ "Sum of digits between $0$ and $"$

$<<$ digit $<<"$ is $"<<$ sum $<<$ endl;

return $0$;

$\}$

$3$ Event$-$controlled Loops

Use program shell CountUC for exercises $4$ and $5.$

$//$ Program CountUC counts the number of uppercase letters

$//$ on a line.

#include

using namespace std;

int main $()$

$\{$

char letter;

int letterCt;

$/*$ TO BE FILLED IN $*/$

return $0$;

$\}$

Exercise $4.$

Fill in the body of program CountUC so that the number of uppercase letters on a line of input is printed.

Run your program with the following input and show the result.

$($Hint: $1.$ Remember that the ASCII code of letters are in alphabetic order, so an uppercase letter must

satisfy letter$>=$A$$ && letter$<=$Z$.$

$2.$ You can use cin.get$($letter$)$ to get each character in the line and exit the loop when it$$s $\text{'}$

$\text{'}.)$

Input Output

AbbaDabbaDoo $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$

Exercise $5.$

Change program CountUC from Exercise $4$ so that the counting stops if the input line contains a digit.

Run your program with the following data and show the results.

Input Output

ABBA$1$DABBA$2$Doo $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$

$4.$ Nested Loops and Testing the State of an I$/$O Stream

Exercises $6$ and $7$ are based on the program SumDigits in Exercise $3.$

Exercise $6$:

Modify your program SumDigits so that the processing is repeated until a negative digit is read. Make

sure you add this information $($the process stops when digit is negative$)$ in the prompt. $($Hint: you need to

implement an outer loop to repeat the prompting and reading data, and keep the summing from $0$ to digit

as an inner loop.$)$

Exercise $7$:

Modify your program in Exercise $6$ so that the values will be read from a file called $$digits$.$dat$$ and the

process is repeated until either a negative digit is read or the end of file. Test both cases.