#include<stdio.h>
#include<malloc.h>
typedef struct sv {
    int mssv;
    struct sv *psvtieptheo;
}sv;
typedef struct DanhSachSinhVien {
    struct sv *head;
}danhsach;
void inDanhSachSV(struct DanhSachSinhVien ds) {
    sv *p = ds.head;
    while(p != NULL)
    {
    printf("%d\n", p->mssv);
    p = p->psvtieptheo;
    }
}
sv themSinhVien1(struct DanhSachSinhVien *ds, int mssv) {
    sv *svmoi = (sv*)malloc(sizeof(sv));
    svmoi->mssv = mssv;
    sv *p1 = ds->head;
    while(p1->psvtieptheo != NULL)
    {
        p1 = p1->psvtieptheo;
    }
    p1->psvtieptheo = svmoi;
    svmoi->psvtieptheo = NULL;
}
sv themSinhVien2(struct DanhSachSinhVien *ds, int mssv1, int mssv2) {
    sv *svmoi1 = (sv*)malloc(sizeof(sv));
    svmoi1->mssv = mssv2;
    sv *pds = ds->head;
    while(pds != NULL)
    {
        if(pds->mssv == mssv1) {
            svmoi1->psvtieptheo = pds->psvtieptheo;
            pds->psvtieptheo = svmoi1;
            break;
        }
        pds = pds->psvtieptheo;
    }
}
sv xoaSinhVien(struct DanhSachSinhVien* ds, int mssv) {
	sv *pds = ds->head;
	while(pds != NULL) {
		if(ds->head->mssv == mssv) {
			ds->head = pds->psvtieptheo;
			free(pds);
			break;
		}
		if(pds->psvtieptheo->mssv == mssv) {
			sv *p = pds->psvtieptheo;
			pds->psvtieptheo = pds->psvtieptheo->psvtieptheo;
			free(p);
			break;
		}
		pds = pds->psvtieptheo;
	}
}
int main() {
    int mssv1 = 91011;
    int mssv2 = 111213;
    int mssv = 789;
    danhsach ds;
    danhsach *p2 = &ds;

    sv *sv1 = (sv*)malloc(sizeof(sv));
    ds.head = sv1;
    ds.head->mssv = 123;
    ds.head->psvtieptheo = NULL;

    sv *p = (sv*)malloc(sizeof(sv));
    p = ds.head;

    sv *sv2 = (sv*)malloc(sizeof(sv));
    sv2->mssv = 345;
    sv2->psvtieptheo = NULL;
    sv1->psvtieptheo = sv2;

    sv *sv3 = (sv*)malloc(sizeof(sv));
    sv3->mssv = 567;
    sv3->psvtieptheo = NULL;
    sv2->psvtieptheo = sv3;

    sv *sv4 = (sv*)malloc(sizeof(sv));
    sv4->mssv = mssv1;
    sv3->psvtieptheo = sv4;
    sv4->psvtieptheo = NULL;

    themSinhVien2(p2, mssv1, mssv2);

    themSinhVien1(p2, mssv);

    xoaSinhVien(p2, 111213);

    inDanhSachSV(ds);

    return 0;
}