Question

Assignment 12 The program to write in this assignment is a program that calculates score statistics and manages the grades of the students. First, the student list and scores are given in a file named "student.dat" as in the following: 이성우 77 홍길동 88 2011710086 2012700091 This program reads the input file "student.dat" and keeps this data in a linear linked list. Each node must be a struct which contains the following: student_id, student_name, score, grade The grades are decided by each students' scores: if 90 score, grade A if 70 s score <80, grade C if score < 60, grade F if 80 s score < 90, grade B if 60 s score < 70, grade = D Basis and Practice in Programming Assignment 12 This program must include the following functions: 1) Calculate mean and standard deviation: Given student scores x, i= 1, , n(= no. of students), it must calculate the ,and Standard Deviation Mean, de- 2) Searching student information: Search within the linear linked list with the student id or student name, and print the following student id 2012700091 If there is no such student in the record, then the program prints "no such student! student name 홍길동 grade B score 88 3) Change student score: Search through the linear linked list with the student id or student_name, and change the score of that student. The grade must be changed according to the new score. If there is no such student in the record, then the program prints "no such student!" Basis and Practice in Programming
in C porgraming . use #include〈stdio.h〉

#include〈stdlib.h〉

Answer 1

CODE:

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>

typedef struct Student{
    char student_id[11];
    char student_name[20];
    int score;
    char grade;
} Student;

typedef struct Node{
    Student s;
    struct Node *next;
} Node;

//Function to add to linked list
Node* add(Node *list, Student s){
    Node *newNode = (Node*)malloc(sizeof(Node));
    newNode->s = s;
    newNode->next = NULL;

    if(list == NULL)
        list = newNode;
    else {
        Node *ptr = list;
        while (ptr->next != NULL)
            ptr = ptr->next;
        ptr->next = newNode;
    }
    return list;
}

//Function to return grade based on score
char getGrade(int score){
    if(score >= 90)
        return 'A';
    else if(score >= 80)
        return 'B';
    else if(score >= 70)
        return 'C';
    else if(score >= 60)
        return 'D';
    else
        return 'F';
}

//Function to read data from file into linked list
Node* readFromFile(Node *list){
    FILE *f = fopen("student.dat", "r");//Open file in read mode
    if(f == NULL){
        printf("Error: Unable to open file\n");
        exit(EXIT_FAILURE);
    }
    Student s;
    while(!feof(f)){
        fscanf(f, "%s %s %d", s.student_id, s.student_name, &s.score);//Read a record
        s.grade = getGrade(s.score);//Get grade based upon score
        list = add(list, s);
    }
    fclose(f);//Close file
    return list;
}

//Function to return mean of student scores
double getMean(Node *list){
    Node *ptr = list;
    int n = 0;
    double mean = 0.0;
    while(ptr != NULL){
        mean += ptr->s.score;
        n++;
        ptr = ptr->next;
    }
    mean = mean/n;
    return mean;
}

//Function to return standard deviation of student scores
double getStandardDeviation(Node *list){
    Node *ptr = list;
    double mean = getMean(list);
    double sd = 0;
    int n = 0;
    while(ptr != NULL){
        sd += pow(ptr->s.score - mean, 2);
        n++;
        ptr = ptr->next;
    }
    sd = sqrt(sd/(n - 1));
    return sd;
}

//Function to search linked list for student with student id
void searchWithStudentID(Node *list, char *student_id){
    Node *ptr = list;
    while(ptr != NULL){
        if(strcmp(ptr->s.student_id, student_id) == 0){
            printf("student_id\tstudent_name\tscore\tgrade\n");
            printf("%s\t%s\t\t%d\t%c\n", ptr->s.student_id, ptr->s.student_name, ptr->s.score, ptr->s.grade);
            return;
        }
        ptr = ptr->next;
    }
    printf("No such student!\n");
}

//Function to change student score by searching linked list using student id
void changeScore(Node *list, char *student_id){
    Node *ptr = list;
    int score;
    while(ptr != NULL){
        if(strcmp(ptr->s.student_id, student_id) == 0){
            printf("Enter new score: ");
            scanf("%d", &score);
            ptr->s.score = score;
            ptr->s.grade = getGrade(score);
            return;
        }
        ptr = ptr->next;
    }
    printf("No such student!\n");
}

int main(){
    Node *list = NULL;//Create an empty list

    list = readFromFile(list);

    printf("Mean of student scores: %f\n", getMean(list));
    printf("Standard deviation of student scores: %f\n", getStandardDeviation(list));

    printf("\nSearching for student with id 2011710088:\n");
    searchWithStudentID(list, "2011710088");

    printf("\nSearching for student with id 2011710095:\n");
    searchWithStudentID(list, "2011710095");

    printf("\nChanging score of student with id 2011710088:\n");
    changeScore(list, "2011710088");

    printf("\nChanging score of student with id 2011710095:\n");
    changeScore(list, "2011710095");

    return 0;
}

Sample student.dat file:

| student.dat Notepad File Edit Format View Help 2011710086 Jack 77 2011710087 Abel 88 2011710088 Cain 83 2011710089 Eve 96 2011710090 Adam 72 2011710091 Josh 79

Sample terminal output:

CAUsers\Shubham\Desktop\readSquare.exe Mean of student scores: 82.500000 Standard deviation of student scores: 8.549854 Searching for student with id 2011710088: student_name Cain student_id 2011710088 grade score 83 B Searching for student with id 2011710095: No such student! Changing score of student with id 2011710088: Enter new score: 98 Searching for student with id 2011710088: student id 2011710088 student_name Cain grade score 98 A Changing score of student with id 2012700091: No such student! Process exited after 3.682 seconds with return value 0 Press any key to continue

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