qwe/b6.c

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

#define MAX_STUDENTS 100

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

int compare(const void *a, const void *b) {
    Student *s1 = (Student *)a;
    Student *s2 = (Student *)b;
    if (s1->classNum!= s2->classNum) {
        return s1->classNum - s2->classNum;
    }
    double sum1 = s1->score1 + s1->score2 + s1->score3;
    double sum2 = s2->score1 + s2->score2 + s2->score3;
    return (sum2 > sum1) - (sum2 < sum1);
}

int findByID(Student students[], int n, char id[]) {
	int i;
    for ( i = 0; i < n; i++) {
        if (strcmp( students[i].id,id) == 0) {
            return i;
        }
    }
    return -1;
}

void modifyStudent(Student students[], int n, char id[], int newClass, char newName[], 
                    double newScore1, double newScore2, double newScore3) {
    int index = findByID(students, n, id);
    if (index!= -1) {
        students[index].classNum = newClass;
        strcpy(students[index].name, newName);
        students[index].score1 = newScore1;
        students[index].score2 = newScore2;
        students[index].score3 = newScore3;
    }
}

void printStudents(Student students[], int n,char inputID[]) {
    int currentClass = -1;
    int i;
    for ( i = 0; i < n; i++) {
        if (students[i].classNum!= currentClass) {
            if (i!= 0) {
                printf("\n");
            }
            currentClass = students[i].classNum;
            printf("%d %s %s %.1lf %.1lf %.1lf", currentClass, students[i].id, students[i].name,
                   students[i].score1, students[i].score2, students[i].score3);
            if (i == findByID(students, n, inputID)) {
                printf(" modified");
            }
            printf("\n");
        } else {
            printf("   %s %s %.1lf %.1lf %.1lf", students[i].id, students[i].name,
                   students[i].score1, students[i].score2, students[i].score3);
         if (i == findByID(students, n, inputID)) {
                printf(" modified");}
        printf("\n");
    }
}
}

int main() {
    Student students[MAX_STUDENTS];
    int numStudents = 3;

    // ???????????
    strcpy(students[0].id, "10001");
    students[0].classNum = 11;
    strcpy(students[0].name, "Zhang");
    students[0].score1 = 99.5;
    students[0].score2 = 88.5;
    students[0].score3 = 89.5;

    strcpy(students[1].id, "10002");
    students[1].classNum = 12;
    strcpy(students[1].name, "Yang");
    students[1].score1 = 77.9;
    students[1].score2 = 56.5;
    students[1].score3 = 87.5;

    strcpy(students[2].id, "10003");
    students[2].classNum = 11;
    strcpy(students[2].name, "Liang");
    students[2].score1 = 92.5;
    students[2].score2 = 99.0;
    students[2].score3 = 60.5;

    qsort(students, numStudents, sizeof(Student), compare);

    char inputID[20];
    int inputClass;
    char inputName[20];
    double inputScore1, inputScore2, inputScore3;
    printf("please input the student 's information");
    scanf("%s %d %s %lf %lf %lf", inputID, &inputClass, inputName, &inputScore1, &inputScore2, &inputScore3);

    modifyStudent(students, numStudents, inputID, inputClass, inputName, inputScore1, inputScore2, inputScore3);
    printStudents(students, numStudents,inputID);
    
    

    return 0;
}