第二週題目練習.pptx

資料結構實作

題目說明

• 請以C語言設計一個學生成績計算的程式，需要的要求包含:
• 1.先讀取data.txt的檔案, 檔案中有20個學生的資料檔, 包含學號,姓名, 國文成績, 英文成績, 數學成績。 若無法讀取檔案, 請顯示”The file can’t open”。
• 2.請設計一個結構, 結構名稱為scores, 裏面包含chinese, english, math三個成績的宣告。
• 3.請設計一個結構, 結構名稱為student方式來宣告id, name, structure scores, total_score, average_score, rank。
• 3.請利用副程式Calculate的方式去計算每位學生的總成績與平均成績(請算到小數點第2位)。
• 4.利用副程式Rank來計算所有學生的名次。
• 5.最後請列印出20位學生所有成績的執行結果, 輸出結果如範例. 每個欄位都用一個TAB隔開出欄位距離。

輸入資料 data.txt

1001 John 85.5 90.0 78.5 1002 Mary 76.0 88.5 92.0 1003 David 92.5 87.0 89.5 1004 Lisa 78.5 76.0 81.5 1005 Kevin 89.0 92.0 90.5 1006 Sarah 93.5 85.0 88.0 1007 Michael 81.0 78.0 87.5 1008 Jessica 87.0 89.5 95.0 1009 Andrew 90.5 82.0 79.0 1010 Emily 95.0 91.0 87.0 1011 Brian 84.0 76.5 83.5 1012 Olivia 88.5 92.0 91.5 1013 Christ 77.5 84.0 79.5 1014 Sophia 93.0 87.5 90.5 1015 Daniel 80.0 86.5 88.0 1016 Emma 89.5 90.0 92.0 1017 Ethan 82.5 79.5 83.0 1018 Mia 86.0 88.0 89.5 1019 Benn 91.5 94.0 90.5 1020 Ava 88.5 85.0 83.5

data.txt

輸出結果

My Code:

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

// class score 
struct scores {
    float chinese;
    float english;
    float math;
};

// class student
struct student {
    int id;
    char name[50];
    struct scores student_scores;
    float total_score;
    float average_score;
    int rank;
};

//Arrow operator -> , allows to access elements in Structures and Unions. It is used with a pointer variable pointing to a structure or union. 
//The arrow operator is formed by using a minus sign, followed by the greater than symbol as shown below.
//(pointer_name)->(variable_name) 
void Calculate(struct student *s) {
    s->total_score = s->student_scores.chinese + s->student_scores.english + s->student_scores.math;
    s->average_score = s->total_score / 3;
}

// rank, count who is better than me
void Rank(struct student students[], int n) {
    for (int i = 0; i < n; i++) {
        students[i].rank = 1;
        for (int j = 0; j < n; j++) {
            if (students[j].total_score > students[i].total_score) {
                students[i].rank++;
            }
        }
    }
}

int main() {
//	FILE is a variable in stdio.h
    FILE *file; 
    file = fopen("data.txt", "r");
    
//  null in stdlib.h
    if (file == NULL) {
        printf("The file can't open\\n");
        return 1;
    }

	    int n = 20; // student num
//	    create an array that is capable of storing 20 students 
	    struct student students[n]; 

    for (int i = 0; i < n; i++) {
        fscanf(file, "%d %s %f %f %f", &students[i].id, students[i].name,
               &students[i].student_scores.chinese, &students[i].student_scores.english,
               &students[i].student_scores.math);

        Calculate(&students[i]);
    }

    Rank(students, n);

    printf("ID\\tName\\tChinese\\tEnglish\\tMath\\tSum\\tAvg\\tRank\\n");
    for (int i = 0; i < n; i++) {
        printf("%d\\t%s\\t%.2f\\t%.2f\\t%.2f\\t%.2f\\t%.2f\\t%d\\n", students[i].id, students[i].name,
               students[i].student_scores.chinese, students[i].student_scores.english,
               students[i].student_scores.math, students[i].total_score,
               students[i].average_score, students[i].rank);
    }

    fclose(file);

    return 0;
}