#include <stdio.h>#include <conio.h>#include <alloc.h>#include <string.h>
// cáu trúc sinh viêntypedef struct tagsinhvien {  char hoten[40];  char mslop[6];  struct tagsinhvien *nexthoten, *nextmslop;} SINHVIEN;
// khai bao list svSINHVIEN *headht, *headms;
// khởi tạovoid initialize(){  headht = (SINHVIEN *)malloc(sizeof(SINHVIEN));  headht->nexthoten = NULL;  headms = (SINHVIEN *)malloc(sizeof(SINHVIEN));  headms->nextmslop = NULL;}
//void release(SINHVIEN *s){  if (s->nexthoten)    release(s->nexthoten);  free(s);}
//void cleanup(){  if (headht->nexthoten)    release(headht->nexthoten);  free(headht);  free(headms);}
//void inds_ht(SINHVIEN *s){  if (s == NULL)    return;  printf("\n%-6s %-40s", s->mslop, s->hoten);  inds_ht(s->nexthoten);}
void inds_ms(SINHVIEN *s){  if (s == NULL)    return;  printf("\n%-6s %-40s", s->mslop, s->hoten);  inds_ms(s->nextmslop);}
void in_hoten(){  if (headht->nexthoten)    inds_ht(headht->nexthoten);}
void in_mslop(){  if (headms->nextmslop)    inds_ms(headms->nextmslop);}
void insert_hoten(SINHVIEN *s){  SINHVIEN *a, *b;  if (headht->nexthoten == NULL)    headht->nexthoten = s;  else  {    a = headht;    b = headht->nexthoten;    while (strcmp(b->hoten, s->hoten)<0 && b!= NULL)    {      a = a->nexthoten;      b = b->nexthoten;    }    a->nexthoten = s;    s->nexthoten = b;  }}
void insert_mslop(SINHVIEN *s){  SINHVIEN *a, *b;  if (headms->nextmslop == NULL)    headms->nextmslop = s;  else  {    a = headms;    b = headms->nextmslop;    while (strcmp(b->mslop, s->mslop)<0 && b!= NULL)    {      a = a->nextmslop;      b = b->nextmslop;    }    a->nextmslop = s;    s->nextmslop = b;  }}
void insert(char *hoten, char *mslop){  SINHVIEN *s;
  s = (SINHVIEN *)malloc(sizeof(SINHVIEN));  strncpy(s->hoten, hoten, 40);  strncpy(s->mslop, mslop, 6);  s->nexthoten = s->nextmslop = NULL;  insert_hoten(s);  insert_mslop(s);}
void nhapds(){  int done = 0;  char hoten[40], mslop[6];  do {    printf("\nNhap ho ten (trong de thoat) : ");    gets(hoten);    if (strcmp(hoten, "") == 0)      done = 1;    else    {      printf("\nNhap ma so lop : ");      gets(mslop);      insert(hoten, mslop);    }  } while (!done);}
// hàm mainvoid main(){  initialize();  nhapds();  printf("\nDanh sach theo ho ten : ");  in_hoten();  printf("\nDanh sach theo ma so lop : ");  in_mslop();    getch();  cleanup();}