Problem Solving Techniques - Lecture Slides | CPE 112, Study notes of Engineering

Download Problem Solving Techniques - Lecture Slides | CPE 112 and more Study notes Engineering in PDF only on Docsity! 1 Electrical and Computer Engineering 1 UAH CPE 112 Problem-Solving Techniques • Ask questions. • Look for things that are familiar. • Solve by analogy. • Identify the inputs and outputs. • Divide and conquer. • Use building blocks (new or existing). • Merge solutions. Electrical and Computer Engineering 2 UAH CPE 112 Problem-Solving Case Study • Problem: A small company needs an interactive program to figure its weekly payroll. The input data and each employee’s wages should be saved in a secondary storage file, and the total wages for the week should be displayed on the screen so that the payroll clerk can transfer the appropriate amount into the payroll account. – Data consists of id, hourly pay rate, and hours worked – Regular wage for 40 hours, time and a half after that – Store results in a file called payFile – Use id 0 to indicate end of data since it is not a valid id Electrical and Computer Engineering 3 UAH CPE 112 • Four obvious steps – Get the data – Compute the results – Output data – Output total payroll Case Study (continued) Payroll Get data Compute results Output data Output total payroll Electrical and Computer Engineering 4 UAH CPE 112 Main Algorithm Open file payFile, Set total payroll to zero Get Data As long as the employee number is not zero Compute Result Add employee’s wages to the total payroll Output data Get data Output total payroll Electrical and Computer Engineering 5 UAH CPE 112 Get Data Prompt user for id number Read id number Prompt user for pay rate Read pay rate Prompt user for number hours worked Read number hours worked Electrical and Computer Engineering 6 UAH CPE 112 Compute Results If hours worked is greater than 40, then Wages = 40 * pay rate + (hours – 40) * 1.5 * pay rate Otherwise Wages = hours * pay rate 2 Electrical and Computer Engineering 7 UAH CPE 112 Output Data Write id number into payFile Write pay rate into payFile Write hours worked into payFile Write wages into payFile Electrical and Computer Engineering 8 UAH CPE 112 Output Total Payroll • Write total payroll to the screen Electrical and Computer Engineering 9 UAH CPE 112 Payroll Program //********************************************* // Payroll program // This program computes each employee’s wages and the // total company payroll //********************************************** #include <iostream> #include <fstream> using namespace std; void CalcPay (float, float, float&); const float MAX_HOURS = 40.0; // Maximum normal hours const float OVERTIME = 1.5; // Overtime pay factor Electrical and Computer Engineering 10 UAH CPE 112 Payroll Program (continued) int main { float payRate; // Employee’s pay rat float hours; // Hours worked float wages; // Wages earned float total; // Total company payroll int empNum; // Employee ID number ofstream payFile; // Company payroll file payFile.open(“payfile.dat”); // Open the output file total = 0.0; // Initialize total Electrical and Computer Engineering 11 UAH CPE 112 Payroll Program (continued) cout << “Enter employee number: ”; // Prompt cin >> empNum; // Read employee id no. while (empNum != 0) // While employee { // number isn’t zero cout << “Enter pay rate: ”; // Prompt cin >> payRate; // Read hourly pay rate cout << “Enter Hours worked: ”; // Prompt cin >> hours; // Read hours worked CalcPay(payRate, hours, wages); // Compute wages total = total + wages; // Add wages to total payFile << empNum << payRage // Put results in file << hours << wages; cout << “Enter employee number: ”; //Prompt cin >> empNum; // Read ID number } cout << “Total payroll is ” // Print total payroll << total << endl; // on screen return 0; // Indicate successful } // completion Electrical and Computer Engineering 12 UAH CPE 112 Payroll Program (continued) //***************************************************** void CalcPay(/* in */ float payRate, // Employee’s pay rate /* in */ float hours, // Hours worked /* out */ float& wages) // Wages earned // CalcPay computes wages from the employee’s pay rate // and the hours worked, taking overtime into account { if (hours > MAX_HOURS; // Is there overtime? wages = (MAX_HOURS * payRate) + // Yes (hours – MAX_HOURS) * payRate * OVERTIME; else wages = hours * payRate; // No }