Practice Programs can generally be solved with a short program that directly applies the programming principles presented in this chapter.
Write a function that computes the average and standard deviation of four scores. The standard deviation is defined to be the square root of the average of the four values: (si – a)2, where a is average of the four scores s1, s2, s3, and s4. The function will have six parameters and will call two other functions. Embed the function in a driver program that allows you to test the function again and again until you tell the program you are finished.
Write a program that reads in a length in feet and inches and outputs the equivalent length in meters and centimeters. Use at least three functions: one for input, one or more for calculating, and one for output. Include a loop that lets the user repeat this computation for new input values until the user says he or she wants to end the program. There are 0.3048 meters in a foot, 100 centimeters in a meter, and 12 inches in a foot.
Write a program like that of the previous exercise that converts from meters and centimeters into feet and inches. Use functions for the subtasks.
(You should do the previous two Practice Programs before doing this one.) Write a program that combines the functions in the previous two Practice Programs. The program asks the user if he or she wants to convert from feet and inches to meters and centimeters or from meters and centimeters to feet and inches. The program then performs the desired conversion. Have the user respond by typing the integer 1 for one type of conversion and 2 for the other conversion. The program reads the user’s answer and then executes an if-else statement. Each branch of the if-else statement will be a function call. The two functions called in the if-else statement will have function definitions that are very similar to the programs for the previous two Practice Programs. Thus, they will be function definitions that call other functions in their function bodies. Include a loop that lets the user repeat this computation for new input values until the user says he or she wants to end the program.
Write a program that reads in a weight in pounds and ounces and outputs the equivalent weight in kilograms and grams. Use at least three functions: one for input, one or more for calculating, and one for output. Include a loop that lets the user repeat this computation for new input values until the user says he or she wants to end the program. There are 2.2046 pounds in a kilogram, 1000 grams in a kilogram, and 16 ounces in a pound.
Write a program like that of the previous exercise that converts from kilograms and grams into pounds and ounces. Use functions for the subtasks.
(You should do the previous two Practice Programs before doing this one.) Write a program that combines the functions of the previous two Practice Programs. The program asks the user if he or she wants to convert from pounds and ounces to kilograms and grams or from kilograms and grams to pounds and ounces. The program then performs the desired conversion. Have the user respond by typing the integer 1 for one type of conversion and 2 for the other. The program reads the user’s answer and then executes an if-else statement. Each branch of the if-else statement will be a function call. The two functions called in the if-else statement will have function definitions that are very similar to the programs for the previous two Practice Programs. Thus, they will be function definitions that call other functions in their function bodies. Include a loop that lets the user repeat this computation for new input values until the user says he or she wants to end the program.
(You need to do Practice Programs 4 and 7 before doing this one.) Write a program that combines the functions of Practice Programs 4 and 7. The program asks the user if he or she wants to convert lengths or weights. If the user chooses lengths, then the program asks the user if he or she wants to convert from feet and inches to meters and centimeters or from meters and centimeters to feet and inches. If the user chooses weights, a similar question about pounds, ounces, kilograms, and grams is asked. The program then performs the desired conversion. Have the user respond by typing the integer 1 for one type of conversion and 2 for the other. The program reads the user’s answer and then executes an if-else statement. Each branch of the if-else statement will be a function call. The two functions called in the if-else statement will have function definitions that are very similar to the programs for Practice Programs 4 and 7. Thus, these functions will be function definitions that call other functions in their function bodies; however, they will be very easy to write by adapting the programs you wrote for Practice Programs 4 and 7.
Notice that your program will have if-else statements embedded inside of if-else statements, but only in an indirect way. The outer if-else statement will include two function calls as its two branches. These two function calls will each in turn include an if-else statement, but you need not think about that. They are just function calls and the details are in a black box that you create when you define these functions. If you try to create a four-way branch, you are probably on the wrong track. You should only need to think about two-way branches (even though the entire program does ultimately branch into four cases). Include a loop that lets the user repeat this computation for new input values until the user says he or she wants to end the program.
The area of an arbitrary triangle can be computed using the formula
where a, b, and c are the lengths of the sides, and s is the semiperimeter.
Write a void function that computes the area and perimeter (not the semiperimeter) of a triangle based on the length of the sides. The function should use five parameters—three value parameters that provide the lengths of the edges and two reference parameters that store the computed area and perimeter. Make your function robust. Note that not all combinations of a, b, and c produce a triangle. Your function should produce correct results for legal data and reasonable results for illegal combinations.