cscyzyby/cs6.cpp

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

#define MAX_STUDENTS 100

typedef struct {
    char id[20];
    char clas[20];
    char name[20];
    double score1;
    double score2;
    double score3;
    double totalScore;
} Student;

// Comparison function for sorting
int compareStudents(const void *a, const void *b) {
    Student *studentA = (Student *)a;
    Student *studentB = (Student *)b;
    int classComparison = strcmp(studentA->clas, studentB->clas);
    if (classComparison != 0) {
        return classComparison;
    } else {
        return (studentB->totalScore - studentA->totalScore > 0) ? 1 : -1;
    }
}

void modifyStudent(Student students[], int *count) {
    char id[20], clas[20], name[20];
    double score1, score2, score3;

    printf("Enter student id to modify: ");
    scanf("%s", id);
    for (int i = 0; i < *count; i++) {
        if (strcmp(students[i].id, id) == 0) {
            printf("Enter class, name, score1, score2, score3: ");
            scanf("%s %s %lf %lf %lf", clas, name, &score1, &score2, &score3);
            strcpy(students[i].clas, clas);
            strcpy(students[i].name, name);
            students[i].score1 = score1;
            students[i].score2 = score2;
            students[i].score3 = score3;
            students[i].totalScore = score1 + score2 + score3;
            qsort(students, *count, sizeof(Student), compareStudents);
            printf("Student modified.\n");
            return;
        }
    }
    printf("Student not found.\n");
}

void printStudents(const Student students[], int count) {
    for (int i = 0; i < count; i++) {
        if (i == 0 || strcmp(students[i].clas, students[i-1].clas) != 0) {
            printf("%s ", students[i].clas);
        }
        printf("%s %s %.1f %.1f %.1f", students[i].id, students[i].name, students[i].score1, students[i].score2, students[i].score3);
        if (i == count - 1 || strcmp(students[i+1].clas, students[i].clas) != 0) {
            printf(" \n");
        } else {
            printf(" modified\n");
        }
    }
}

int main() {
    Student students[MAX_STUDENTS] = {
        {"10001", "11", "Zhang", 99.5, 88.5, 89.5, 277.5},
        {"10002", "12", "Yang", 77.9, 56.5, 87.5, 221.9},
        {"10003", "11", "Liang", 92.5, 99.0, 60.5, 252.0}
    };
    int studentCount = 3;

    qsort(students, studentCount, sizeof(Student), compareStudents);

    modifyStudent(students, &studentCount);
    printStudents(students, studentCount);

    return 0;
}