#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;
}

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

void deleteStudent(Student students[], int *n, int index) {
	int i;
    for ( i= index; i < *n - 1; i++) {
        students[i] = students[i + 1];
    }
    (*n)--;
}

int main() {
    Student students[MAX_STUDENTS];
    int numStudents = 3;
 	int i;
    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 input[20];
    printf("please input the id or name you want to delete:");
    scanf("%s", input);

    int index = findByID(students, numStudents, input);
    if (index == -1) {
        index = findByName(students, numStudents, input);
    }

    if (index == -1) {
        for ( i = 0; i < numStudents; i++) {
            printf("%s %d %s %.1lf %.1lf %.1lf\n", students[i].id, students[i].classNum, students[i].name,
                   students[i].score1, students[i].score2, students[i].score3);
        }
    } else {
        
        printf("Are you sure(yes/no)? ");
        char confirm[10];
        scanf("%s", confirm);
        if (strcmp(confirm, "y") == 0) {
             deleteStudent(students, &numStudents, index);
            qsort(students, numStudents, sizeof(Student), compare);
            for ( i = 0; i < numStudents; i++) {
                printf("%s %d %s %.1lf %.1lf %.1lf\n", students[i].id, students[i].classNum, students[i].name,
                       students[i].score1, students[i].score2, students[i].score3);
            }
    	}
            if (strcmp(confirm, "n") == 0)
            {
            	for ( i = 0; i < numStudents; i++) {
            printf("%s %d %s %.1lf %.1lf %.1lf\n", students[i].id, students[i].classNum, students[i].name,
                   students[i].score1, students[i].score2, students[i].score3);
			}
        }
    }

    return 0;
}