Repeat C program and output scores

I have written a program in C language. The program is designed for primary school students in Grades 1-2. Two integers are randomly selected, the numbers are either added or subtracted to form an equation, and the students are asked to solve the equation.

Code criteria:
a. Each round of the game consists of 10 questions that are not to be repeated. 10 marks for each question. Each round of games is required to be set anew and is not have the same questions as the previous rounds.


b. Only the addition and subtraction within 100 is allowed, the sum and difference of the two numbers should not exceed the range of 100, and is not to have a negative value.


c. For each question, players have 3 chances to enter their answers. 10 points are awarded for the first correct attempt, 7 points for the second attempt, 5 points for the third attempt, zero points if all 3 attempts failed. When an incorrect answer is entered, a message should appear prompting the student to re-enter the answer. Output the correct answer if all 3 attempts are used in the form "No, the answer is X".


d. At the end of the test, a message should appear prompting the player to choose "Show results", by entering the letter "S", "Play another round", by entering the letter "P", and "Quit", by entering the letter "Q". If the player entered "S" after one round of the game, output the player's score (marks/100). If the player chooses "Show results" after multiple rounds of the game, the output should include the player's highest score/%, lowest score/%, and the average score/% of all games played. If the player enters "Q", the program ends.


e. Include fault tolerance function, a simple menu interface, necessary notes. The program should also meet the requirements of modularization and structurization.

This is my code:

Code:

---

#include<stdio.h>
#include <stdlib.h>
#include <time.h>

struct struc { int a;

              int b;

              int c;

              int add;

              int grade;

              };





int sj(int n)

{ int t;

            t=rand()%n;

            return t;

            }





void ctm_i(struct struc *t)

            { t->a=sj(101);

            t->c=sj(4);

            if(t->c==1) { t->b=sj(101-(t->a));

                        t->add=(t->a)+(t->b);}

  else { t->b=sj((t->a)+1);

        t->add=(t->a)-(t->b);}

  t->grade=10;

 }



void tcm_i(struct struc *t,int n)

 { int ad;

printf(" ********************************************************************************\n");

    printf(" ................................................................................\n");

  printf(" Question %d\n\n",n+1);

  printf(" You have 3 attempts for this question\n\n");

  if(t->c==1)printf(" %d+%d= ",t->a,t->b);

  else printf(" %d-%d= ",t->a,t->b);

scanf(" %d",&ad);

if(ad==t->add)

    { t->grade=10;

      printf("\n Very good, you earned 10 marks\n\n");

      }

  else { printf("\n Sorry, you have 2 attempts remaining\n\n");

scanf(" %d",&ad);

if(ad==t->add)

            { t->grade=7;

              printf("\n Good, you earned 7 marks\n\n");

            }

        else { printf("\n Sorry, you have 1 attempt remaining\n\n");

scanf(" %d",&ad);

if(ad==t->add)

                  { t->grade=5;

                  printf("\n Not bad, you earned 5 marks\n\n");

                  }

              else { t->grade=0;

                  printf("\n Failure, 0 mark\n\n");

                  printf("\n The correct answer is%d\n\n",t->add);

                      }

                }

        }

    printf(" ................................................................................\n");

printf(" ********************************************************************************\n");

    }





int main()

 { int i,j,g=0;

  char x;

  struct struc test[10];

  srand((unsigned)time(NULL));

  printf(" ***********************************************************************************\n");

printf(" ...................................................................................\n");

  printf(" ****************************Welcome!****************************\n\n");

  printf(" ...........This program is for students Grades 1-2............\n");

  printf("\n Description:\n");

  printf("（1）Computer randomly selects 10 questions, each question is worth 10 points, the end of the test shows the student score；\n");

  printf("（2）Only addition and subtraction within 100 is allowed. The sum or difference of two numbers do not exceed the range of 0-100, negative numbers are not included；\n");

  printf("（3）There are 3 attempts for each question.；\n");

  printf("（4）For each question, 10 points will be awarded for the first successful attempt, 7 points for the second attempt, and 5 points for the third attempt；\n");

  printf("（5）For total scores above output“EXCELLENT”,80-90“GOOD”，70-80“AVERAGE”,60-70“PASS”，60“POOR“。\n");



  printf(" ................................................................................\n");

printf(" ********************************************************************************\n");

 for(i=0;i<=9;i++)

    { ctm_i(&test[i]);

      for(j=0;j<i;j++)

          if(test[i].a==test[j].a&&test[i].b==test[j].b&&test[i].c==test[j]  .c)

              ctm_i(&test[i]);

      }

printf(" Are you ready? Please click on any key to continue: ");

  scanf("%c",&x);

  for(i=1;i<=5;i++)

{ printf(" ********************************************************************************\n");

    printf(" ................................................................................\n");

}

for(i=0;i<=9;i++)

tcm_i(&test[i],i);

  printf(" End");

  for(i=0;i<=9;i++)

g=g+test[i].grade;

  if(g>90) printf(" Excellent! You are a genius!\n\n");

  else if (g>80) printf(" Not bad, keep it up!\n\n");

      else if (g>70) printf(" Try harder next time!\n\n");

            else printf(" TRY AGAIN\n\n");

  }

---

This is my program output:
Attachment 16241
Attachment 16244
Attachment 16242
Attachment 16243

How do I fulfill criteria d? I know I might use a while loop but I don't know where to place it. Besides, I have no idea how to output the scores required in criteria d, I have only managed to set the program to include certain words of encouragement for a designated range of scores. Lastly, how do I include a fault tolerance function? After inputting the letter "a" into one of the equations, the program just ends. I need a message to prompt the user to input a number.

Criteria not fulfilled:

d. At the end of the test, a message should appear prompting the player to choose "Show results", by entering the letter "S", "Play another round", by entering the letter "P", and "Quit", by entering the letter "Q". If the player entered "S" after one round of the game, output the player's score (marks/100). If the player chooses "Show results" after multiple rounds of the game, the output should include the player's highest score/%, lowest score/%, and the average score/% of all games played. If the player enters "Q", the program ends.

Any help would be greatly appreciated.

I would suggest that the first thing to do is to format your code properly, especially where indentation is concerned. For example:

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

struct struc
{
    int a;
    int b;
    int c;
    int add;
    int grade;
};

int sj(int n)
{
    int t;
    t = rand() % n;
    return t;
}

void ctm_i(struct struc *t)
{
    t->a = sj(101);
    t->c = sj(4);
    if (t->c == 1)
    {
        t->b = sj(101 - (t->a));
        t->add = (t->a) + (t->b);
    }
    else
    {
        t->b = sj((t->a) + 1);
        t->add = (t->a) - (t->b);
    }
    t->grade = 10;
}

void tcm_i(struct struc *t, int n)
{
    int ad;
    printf(" ********************************************************************************\n");
    printf(" ................................................................................\n");
    printf(" Question %d\n\n",n+1);
    printf(" You have 3 attempts for this question\n\n");
    if (t->c == 1)
        printf(" %d+%d= ", t->a, t->b);
    else
        printf(" %d-%d= ", t->a, t->b);
    scanf(" %d", &ad);

    if (ad == t->add)
    {
        t->grade = 10;
        printf("\n Very good, you earned 10 marks\n\n");
    }
    else
    {
        printf("\n Sorry, you have 2 attempts remaining\n\n");
        scanf(" %d", &ad);
        if (ad == t->add)
        {
            t->grade = 7;
            printf("\n Good, you earned 7 marks\n\n");
        }
        else
        {
            printf("\n Sorry, you have 1 attempt remaining\n\n");
            scanf(" %d",&ad);
            if (ad == t->add)
            {
                t->grade = 5;
                printf("\n Not bad, you earned 5 marks\n\n");
            }
            else
            {
                t->grade = 0;
                printf("\n Failure, 0 mark\n\n");
                printf("\n The correct answer is%d\n\n", t->add);
            }
        }
    }

    printf(" ................................................................................\n");
    printf(" ********************************************************************************\n");
}

int main()
{
    int i, j, g = 0;
    char x;
    struct struc test[10];

    srand((unsigned)time(NULL));

    printf(" ***********************************************************************************\n");
    printf(" ...................................................................................\n");
    printf(" ****************************Welcome!****************************\n\n");
    printf(" ...........This program is for students Grades 1-2............\n");
    printf("\n Description:\n");
    printf("（1）Computer randomly selects 10 questions, each question is worth 10 points, the end of the test shows the student score；\n");
    printf("（2）Only addition and subtraction within 100 is allowed. The sum or difference of two numbers do not exceed the range of 0-100, negative numbers are not included；\n");
    printf("（3）There are 3 attempts for each question.；\n");
    printf("（4）For each question, 10 points will be awarded for the first successful attempt, 7 points for the second attempt, and 5 points for the third attempt；\n");
    printf("（5）For total scores above output“EXCELLENT”,80-90“GOOD”，70-80“AVERAGE”,60-70“PASS”，60“POOR“。\n");
    printf(" ................................................................................\n");
    printf(" ********************************************************************************\n");

    for (i = 0; i <= 9; i++)
    {
        ctm_i(&test[i]);
        for (j = 0; j < i; j++)
            if (test[i].a == test[j].a && test[i].b == test[j].b && test[i].c == test[j].c)
                ctm_i(&test[i]);
    }

    printf(" Are you ready? Please click on any key to continue: ");
    scanf("%c", &x);

    for (i = 1; i <= 5; i++)
    {
        printf(" ********************************************************************************\n");
        printf(" ................................................................................\n");
    }

    for (i = 0; i <= 9; i++)
        tcm_i(&test[i], i);

    printf(" End");

    for (i = 0; i <= 9; i++)
        g = g + test[i].grade;

    if (g > 90)
        printf(" Excellent! You are a genius!\n\n");
    else if (g > 80)
        printf(" Not bad, keep it up!\n\n");
    else if (g > 70)
        printf(" Try harder next time!\n\n");
    else
        printf(" TRY AGAIN\n\n");
}

---

As you can see, each code block is indented by one indent level, and it goes up by one when you enter a more nested code block, then down again when you leave the nested code block. I chose to use 4 spaces per indent level, but generally anywhere between 2 to 8 spaces (typically 2, 4, or 8) or one tab character will do, as long as you are consistent. I chose a consistent brace placement style; again there are a few common styles available, but be consistent, at least within each project you work on. I have also inserted whitespace to make parts of the code more readable; this is purely subjective style, so it is up to you what you want to adopt or chose your own style. Notice the judicious use of blank lines to separate parts of the code.

A rule of thumb is that the larger the scope of a name, the more descriptive the name should be. So something like a struct name or a function name should be very descriptive. struct struc doesn't tell us anything about what the struct represents. a, b, and c as member names don't really tell us what they are about either, although you might be able to keep them and just provide a comment explaining what they mean. add is a bit better, but not much. What are sj, ctm_i, and tcm_i?

Quote:

---

Originally Posted by Eve Wein

How do I fulfill criteria d? I know I might use a while loop but I don't know where to place it.

---

Move code from your main function that deals with a round of the game into a function. Then, you can have a loop in the main function that calls this new function, getting its results for the statistics processing.

Here's a hint:

Code:

---

#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define MAX_TESTS 10

bool read(const char* format, void* address) {
  char buffer[1024];
  fgets(buffer, sizeof buffer, stdin);
  return sscanf(buffer, format, address) == 1;
}

struct struc {
  int a;

  int b;

  int c;

  int add;

  int grade;
};

int sj(int n)
{
  int t;

  t = rand() % n;

  return t;
}

void ctm_i(struct struc* t)
{
  t->a = sj(101);

  t->c = sj(4);

  if (t->c == 1) {
    t->b = sj(101 - (t->a));

    t->add = (t->a) + (t->b);
  }

  else {
    t->b = sj((t->a) + 1);

    t->add = (t->a) - (t->b);
  }

  t->grade = 10;
}

void tcm_i(struct struc* t, int n)
{
  int ad;

  printf(
      " ***********************************************************************"
      "*********\n");

  printf(
      " ......................................................................."
      ".........\n");

  printf(" Question %d\n\n", n + 1);

  printf(" You have 3 attempts for this question\n\n");

  if (t->c == 1)
    printf(" %d+%d= ", t->a, t->b);

  else
    printf(" %d-%d= ", t->a, t->b);

  read(" %d", &ad);

  if (ad == t->add)

  {
    t->grade = 10;

    printf("\n Very good, you earned 10 marks\n\n");

  }

  else {
    printf("\n Sorry, you have 2 attempts remaining\n\n");

    read(" %d", &ad);

    if (ad == t->add)

    {
      t->grade = 7;

      printf("\n Good, you earned 7 marks\n\n");

    }

    else {
      printf("\n Sorry, you have 1 attempt remaining\n\n");

      read(" %d", &ad);

      if (ad == t->add)

      {
        t->grade = 5;

        printf("\n Not bad, you earned 5 marks\n\n");

      }

      else {
        t->grade = 0;

        printf("\n Failure, 0 mark\n\n");

        printf("\n The correct answer is %d\n\n", t->add);
      }
    }
  }

  printf(
      " ......................................................................."
      ".........\n");

  printf(
      " ***********************************************************************"
      "*********\n");
}

int main()
{
  int rounds = 0;
  int highest = 0;
  int lowest = INT_MAX;

  int i, j, g = 0;

  char x;

  struct struc test[MAX_TESTS];

  srand((unsigned)time(NULL));

  printf(
      " ***********************************************************************"
      "************\n");

  printf(
      " ......................................................................."
      "............\n");

  printf(
      " ****************************Welcome!****************************\n\n");

  printf(" ...........This program is for students Grades 1-2............\n");

  printf("\n Description:\n");

  printf(
      "（1）Computer randomly selects 10 questions, each question is worth 10 "
      "points, the end of the test shows the student score；\n");

  printf(
      "（2）Only addition and subtraction within 100 is allowed. The sum or "
      "difference of two numbers do not exceed the range of 0-100, negative "
      "numbers are not included；\n");

  printf("（3）There are 3 attempts for each question.；\n");

  printf(
      "（4）For each question, 10 points will be awarded for the first "
      "successful attempt, 7 points for the second attempt, and 5 points for "
      "the third attempt；\n");

  printf(
      "（5）For total scores above "
      "output“EXCELLENT”,80-90“GOOD”，70-80“AVERAGE”,60-"
      "70“PASS”，60“POOR“。\n");

  printf(
      " ......................................................................."
      ".........\n");

  printf(
      " ***********************************************************************"
      "*********\n");

  for (i = 0; i < MAX_TESTS; i++)

  {
    ctm_i(&test[i]);

    for (j = 0; j < i; j++)

      if (test[i].a == test[j].a && test[i].b == test[j].b &&
          test[i].c == test[j].c)

        ctm_i(&test[i]);
  }

  printf(" Are you ready? Please click on any key to continue: ");

  getchar();

  for (;;) {
    rounds++;

    for (i = 1; i <= 5; i++) {
      printf(
          " *******************************************************************"
          "**"
          "***********\n");

      printf(
          " ..................................................................."
          ".."
          "...........\n");
    }

    for (i = 0; i < MAX_TESTS; i++) tcm_i(&test[i], i);

    printf(" End");

    for (i = 0; i < MAX_TESTS; i++) g = g + test[i].grade;

    if (g > 90)
      printf(" Excellent! You are a genius!\n\n");

    else if (g > 80)
      printf(" Not bad, keep it up!\n\n");

    else if (g > 70)
      printf(" Try harder next time!\n\n");

    else
      printf(" TRY AGAIN\n\n");

    bool done = false;
    bool unsure = true;

    while (unsure) {
      unsure = false;
      puts("(S)how results");
      puts("(P)lay another round");
      puts("(Q)uit");
      char choice;
      read("%c", &choice);
      if (choice == 'Q')
        done = true;
      else if (choice == 'S') {
        if (rounds == 1)
          printf("Final score: %d/100\n", g);
        else {
          puts("Whoops! Looks like highest/lowest have not been adjusted!");
          printf("Highest score: %d/100\n", highest);
          printf("Lowest score: %d/100\n", lowest);
        }
        getchar();
      } else if (choice == 'P') {
        // Do nothing?
      } else {
        puts("Invalid input!");
        unsure = true;
      }
    }
    if (done) break;
  }
}

---

Quote:

---

Originally Posted by Sir Galahad

Here's a hint:

Code:

---

#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define MAX_TESTS 10

bool read(const char* format, void* address) {
  char buffer[1024];
  fgets(buffer, sizeof buffer, stdin);
  return sscanf(buffer, format, address) == 1;
}

struct struc {
  int a;

  int b;

  int c;

  int add;

  int grade;
};

int sj(int n)
{
  int t;

  t = rand() % n;

  return t;
}

void ctm_i(struct struc* t)
{
  t->a = sj(101);

  t->c = sj(4);

  if (t->c == 1) {
    t->b = sj(101 - (t->a));

    t->add = (t->a) + (t->b);
  }

  else {
    t->b = sj((t->a) + 1);

    t->add = (t->a) - (t->b);
  }

  t->grade = 10;
}

void tcm_i(struct struc* t, int n)
{
  int ad;

  printf(
      " ***********************************************************************"
      "*********\n");

  printf(
      " ......................................................................."
      ".........\n");

  printf(" Question %d\n\n", n + 1);

  printf(" You have 3 attempts for this question\n\n");

  if (t->c == 1)
    printf(" %d+%d= ", t->a, t->b);

  else
    printf(" %d-%d= ", t->a, t->b);

  read(" %d", &ad);

  if (ad == t->add)

  {
    t->grade = 10;

    printf("\n Very good, you earned 10 marks\n\n");

  }

  else {
    printf("\n Sorry, you have 2 attempts remaining\n\n");

    read(" %d", &ad);

    if (ad == t->add)

    {
      t->grade = 7;

      printf("\n Good, you earned 7 marks\n\n");

    }

    else {
      printf("\n Sorry, you have 1 attempt remaining\n\n");

      read(" %d", &ad);

      if (ad == t->add)

      {
        t->grade = 5;

        printf("\n Not bad, you earned 5 marks\n\n");

      }

      else {
        t->grade = 0;

        printf("\n Failure, 0 mark\n\n");

        printf("\n The correct answer is %d\n\n", t->add);
      }
    }
  }

  printf(
      " ......................................................................."
      ".........\n");

  printf(
      " ***********************************************************************"
      "*********\n");
}

int main()
{
  int rounds = 0;
  int highest = 0;
  int lowest = INT_MAX;

  int i, j, g = 0;

  char x;

  struct struc test[MAX_TESTS];

  srand((unsigned)time(NULL));

  printf(
      " ***********************************************************************"
      "************\n");

  printf(
      " ......................................................................."
      "............\n");

  printf(
      " ****************************Welcome!****************************\n\n");

  printf(" ...........This program is for students Grades 1-2............\n");

  printf("\n Description:\n");

  printf(
      "（1）Computer randomly selects 10 questions, each question is worth 10 "
      "points, the end of the test shows the student score；\n");

  printf(
      "（2）Only addition and subtraction within 100 is allowed. The sum or "
      "difference of two numbers do not exceed the range of 0-100, negative "
      "numbers are not included；\n");

  printf("（3）There are 3 attempts for each question.；\n");

  printf(
      "（4）For each question, 10 points will be awarded for the first "
      "successful attempt, 7 points for the second attempt, and 5 points for "
      "the third attempt；\n");

  printf(
      "（5）For total scores above "
      "output“EXCELLENT”,80-90“GOOD”，70-80“AVERAGE”,60-"
      "70“PASS”，60“POOR“。\n");

  printf(
      " ......................................................................."
      ".........\n");

  printf(
      " ***********************************************************************"
      "*********\n");

  for (i = 0; i < MAX_TESTS; i++)

  {
    ctm_i(&test[i]);

    for (j = 0; j < i; j++)

      if (test[i].a == test[j].a && test[i].b == test[j].b &&
          test[i].c == test[j].c)

        ctm_i(&test[i]);
  }

  printf(" Are you ready? Please click on any key to continue: ");

  getchar();

  for (;;) {
    rounds++;

    for (i = 1; i <= 5; i++) {
      printf(
          " *******************************************************************"
          "**"
          "***********\n");

      printf(
          " ..................................................................."
          ".."
          "...........\n");
    }

    for (i = 0; i < MAX_TESTS; i++) tcm_i(&test[i], i);

    printf(" End");

    for (i = 0; i < MAX_TESTS; i++) g = g + test[i].grade;

    if (g > 90)
      printf(" Excellent! You are a genius!\n\n");

    else if (g > 80)
      printf(" Not bad, keep it up!\n\n");

    else if (g > 70)
      printf(" Try harder next time!\n\n");

    else
      printf(" TRY AGAIN\n\n");

    bool done = false;
    bool unsure = true;

    while (unsure) {
      unsure = false;
      puts("(S)how results");
      puts("(P)lay another round");
      puts("(Q)uit");
      char choice;
      read("%c", &choice);
      if (choice == 'Q')
        done = true;
      else if (choice == 'S') {
        if (rounds == 1)
          printf("Final score: %d/100\n", g);
        else {
          puts("Whoops! Looks like highest/lowest have not been adjusted!");
          printf("Highest score: %d/100\n", highest);
          printf("Lowest score: %d/100\n", lowest);
        }
        getchar();
      } else if (choice == 'P') {
        // Do nothing?
      } else {
        puts("Invalid input!");
        unsure = true;
      }
    }
    if (done) break;
  }
}

---

---

Thank you! I think I got it!