CSCI100 Introduction to Computing Algorithms Part IV Categories

CSCI-100 Introduction to Computing Algorithms Part IV

• Categories of operations Sequential operations • Carry out a single well-defined task; when that task is finished, the algorithm moves on to the next operation – Add 1 cup of butter to the mixture in the bowl – Subtract the amount of the check from the current account balance Conditional operations • Ask a question and then select the next operation to be executed on the basis of the answer to that question – If the mixture is too dry, then add one-half cup of water to the bowl Iterative operations • Tell us to go back and repeat the execution of a previous block of instructions – Repeat previous operations until mixture has thickened

• Sequential Operations

• Sequential Operations Examples (DONE IN CLASS) Write pseudocode for an algorithm that gets three data values x, y, and z as input and outputs the average of those three values Write pseudocode for an algorithm that gets the radius r of a circle as input. Its output is both the circumference and the area of a circle of radius r

• Conditional and Iterative Operations

• Conditional and Iterative Operations

• Conditional and Iterative Operations Examples (DONE IN CLASS) Write an if/then/else statement that sets the variable y to the value 1 if x ≥ 0. If x < 0 then the statement should set y to the value 2 Write an algorithm that gets as input three data values x, y, and z and outputs the average of these values if the value of x is positive. If the value of x is either zero or negative, your algorithm should not compute the average but should print the error message “Bad Data” instead

• Example Implement an algorithm to multiply two numbers, a and b, using repeated addition Algorithm outline Create a loop that executes exactly b times, with each execution of the loop adding the value of a to a running total (DONE IN CLASS)