Second assignment: Write a arithmetic "software"

• Topic
• Please write a "software" that can automatically generate primary arithmetic topics.
• Allow the program to accept the user to enter the answer, and determine the right and wrong.
• Finally, the total number of pairs/errors is given.

Requirements Analysis:

Basic functions

To achieve addition within 100

Achieve subtraction within 100

To achieve multiplication within 100

Achieve Division within 100

Design:

Programs consist of main and sub-functions

First select the type of topic to be tested, let the user enter the beginning of the problem, the topic randomly generated (1 for addition operation, 2 for subtraction, 3 for multiplication, 4 for division, 5 for the exit system)

int Question_get () is used to calculate the value of four operations, and temp represents the value calculated by the user, and the system automatically compares the answer with the value of temp to output the appropriate prompt. The final output in total answered the number of questions, correct a few words, answered a few wrong way.

Code implementation:

#include <stdlib.h> #include <stdio.h> #include <time.h>int question_get (); int type;void main (void) { int R=0;int e=0;int answer;int n;     Srand ((unsigned) time (NULL)) loop:printf ("Please select the type of topic to be tested:");     printf ("\n1. addition Operation \n2. Subtraction Operation \n3. Multiplication Operation \n4. division Operation \n5. Exit operation \ n"); printf ("\t\t\t Please select (1-5):");   scanf ("%d", &type);  while (1) {int temp;  int flag;  Answer = Question_get ();  printf ("Please answer: \ n");   scanf ("%d", &temp);   while (Temp!=answer) {e++; printf ("\ n answer wrong, try again, please redo \ n");  scanf ("%d", &temp); } r++; printf ("\ n Congratulations!   Answer right \ n ");  printf ("If you continue to press 1, exit please press 0\n");   scanf ("%d", &flag);  while (flag!=0&&flag!=1) {printf ("by other key not valid \ n"), scanf ("%d", &flag);  } if (flag==0) break; else printf ("You have answered%d questions, of which there is a correct%d, error%d \ n", e+r,r,e); Goto Loop;  }} int Question_get () {int a,b,c; Loop:if (type==1) {A=rand ()%99;  b=99-a;  B=rand ()%b;   printf ("%d +%d =?", a, b);    return (A+B);  } else if (type==2) {B=rand ()%99; C=99-b;  C=rand ()%c;  printf ("%d-%d =?", b+c, B);  return (c);  } else if (type==3) {A=rand ()%10;   B=50-a;   B=rand ()%b;  printf ("%d *%d =?", a, b);  return (A*B);  } else if (type==4) {B=rand ()%50;   c=100/b;  while (1) {C=rand ()%c;  if (c!=0) break;  } printf ("%d/%d =?", b*c, B);  return (c);   } else if (type==5) {printf ("\t\t\t exit system \ n");   System ("pause");  Exit (0); } else if (type==0| |   type>5) {printf ("\t\t\t input error, please enter the number in 1-5 \ n");   printf ("\t\t\t Please select (1-5):");   scanf ("%d", &type);  Goto Loop; }   }

　

Program:

Addition Interface:

Subtraction Interface:

Multiplication interface:

Division Interface:

Analysis and Summary:

PSP time-consuming and summary

Summary:

Must be a lot of brain to think, how to design, why to design, must have a clear idea to write code. To first think good ideas and then write, think of the process is very important, and then to achieve.

Psp	Personal Software Process Stage	Time (h)	Time (%)
Design	Specific design	6	11.5
Coding	Specific code	24	46.2
Code Review	Code review	5	9.6
Test	Testing (self-test, code modification)	13	25
Postmortem & Process Improvement Plan	Summarize afterwards and propose process improvement plan	4	7.7

Second assignment: Write a arithmetic "software"