Transcript Flowcharts
Flowcharts Symbol Terminal Symbol: indicates the starting or stopping pointin the logic. Input/Output Symbol: Represents an input or output process in an algorithm Process Symbol: Represents any single process in an algorithm Predefined Process Symbol: Decision Symbol: Represents a decision in the logic involving the comparison Of two values. The three basic control structures 1. Sequence Statemement a Statemement b Statemement c 2. Selection T F Condition p? Statemement a Statemement b Selection (2) F Condition p? T Statemement a 3. Repetition F Condition p? T Statemement block Example 12.1 Add three numbers A program is required to read three numbers, add them together and print their total. • Defining diagram Input Processing Number1 Read three numbers Number2 Add number together Number3 Print total number Output total Solution Algorithm Start Read Number1 Number2 number3 Add numbers to total Print total Stop Example 12.2 Find average temperature • A program is required to prompt the terminal operator for the maximum and minimum temperature readings on a particular day, accept those readings as integers, and calculate and display to the screen the average temperature, calculated by (maximum temperature + minimum temperature)/2. • Defining diagram Input Max_temp Min_temp Processing Output Prompt for temperatures Avg_temp Get temperatures Calculate average temperature Display average temperature Solution Algorithm Example 12.3 Compute mowing time • A program is required to read from the screen the lenght and widht of a rectangular house block, and the lenght and width of the rectangular house that has been built on the block. The algorithm should then compute and display the mowing time required to cut the grass around the house, at the rate of two square metres per minute. • Defining diagram Input Block_lenght Block_width House_lenght House_width Processing Prompt for block measurements Get block measurements Prompt for house measurements Get house measurements Calculate mowing area Calculate mowing time Output Mowing_time Solution Algorithm Flowchart and the selection control structure Simple IF statement T Service_charge = $5 Account_ balance < $300? F Service_charge = $2 Null ELSE statement Combined IF statement Nested IF statement T F Record Code =`A‘ ? F T Record Increment Counter_A Code =`B‘ ? F Record Code =`C‘ Increment Counter_B ? T Increment Counter_C Increment Error_counter Example 12.4 Read three characters • Design an algorithm that will prompt a terminal operator for three characters, accept those characters as input, sort them into ascending sequence and output them to the screen. • Defining diagram Input Char_1 Char_2 Char_3 Processing Prompt for characters Accept three characters Sort three characters Output three characters Output Char_1 Char_2 Char_3 Solution Algorithm ? Case Structure Case Of variable Value 1 Statement_a Value 2 Value 3 Value 4 Statement_b Statement_c Statement_d Flowchart and Array • Design a program that will prompt for and receive 18 examination scores from a mathematics test, compute the class average, and display all the scores and the class average to the screen. • Defining diagram Input 18 exam scores Processing Prompt the scores Get scores Compute class average Display scores Display class average Output 18 exam scores Class_average Control Structures required 1. An array to store the exam scores – called ´scores´ 2. An index to identify each element in the array 3. A DO loop to accept the scores 4. Another DO loop to display the scores to the screen. Solution Algorithm Start Calculate average Total_score = zero Display average I=1 I=1 Stop Prompt and get Scores (I) Display Scores (I) Add scores(I) to Total score I=I+1 T I=I+1 I <= 18 ? F T I <= 18 ? F Flowchart and Module Design a solution algorithm that will prompt a terminal operator for three characters, accept those characters as input, sort them into ascending sequence and output them to the screen. The algorithm is to continue to read characters until ´XXX`is entered. • Defining diagram Input Char_1 Char_2 Char_3 Processing Prompt for characters Accept three characters Sort three characters Output three characters Output Char_1 Char_2 Char_3 Hierarchy chart Process_three_ characters Sort_three_ characters Process_three_characters Start Prompt For characters Get characters F Characters NOT = xxx ? Sort_ Three_ characters Outpur characters Prompt For characters Stop T Get characters Sort_three_characters Thanks Finish!