void main(void)
{
    FLIGHT fltlist[M][N];
    FLIGHT* k;
    k=(FLIGHT*) fltlist;
    ReadFlight(k);
    for(;;)
    {
        char c;
        printf("\t\t\t\t 飞机订票系统\n");
        printf("----------主菜单----------\n");
        printf("\t\t\t\t 1.输入航班信息\n");
        printf("\t\t\t\t 2.输出航班信息\n");   
        printf("\t\t\t\t 3.查找航班信息\n");
        printf("\t\t\t\t a.显示空位数量\n");   
         printf("\t\t\t\t b.显示已订座信息\n");   
        printf("\t\t\t\t c.起飞时间\n");
        printf("\t\t\t\t 4.订票预约\n");   
        printf("\t\t\t\t 5.删除订票预约\n");
        printf("\t\t\t\t 6.退出系统\n");
        printf("--------------------------\n");
        printf("请选择1-6:");
        char m;
        c=getchar();
        switch(c)
        {
case'1':
    {
            shuruFlight(k);
            system("cls");
            getchar();
    }
        break;
case'2':
    {
        shuchuFlight(k);   
        system("cls");
        getchar();
    } break;
case'3':
        {if(chaxunhangban(k)=='y')
        {printf("\n请选择a-c: ");
        scanf("%c",&m);
        c='y';
        while(c=='y'||c=='Y')
        {switch(m)
        {
case'a':{chakongweigeshu(k);}
        break;
case'b':{chakongweixinxi(k);}
        break;
case'c':{chaxunyidingxinxi(k);}
        break;
case'd':{qifeishijian(k);}
        break;
default:printf("没有这个选项！\n按回车键继续其他操作。");
    getchar();
    getchar();
    break;
        }
printf("你还要查询本航班其他信息吗？（具体如下）:\n");
      printf("\t\t\t\t   a.显示空座的数量\n");
      printf("\t\t\t\t   b.显示已订座信息\n");
      printf("\t\t\t\t   c.起飞时间\n");
      printf("请选择(y\n):");
      getchar();
      scanf("%c",&c);
      if(c=='y'||c='Y')
      {printf("\n请选择a-c: ");
      getchar();
      scanf("%c",&m);}
      else
      {system("cls");
      getchar();
      break;
        }
        }
        }
        else system("cls");
        }
      break;
      case'4':
      {k=(FLIGHT*) fltlist;
      book(k);
      system("cls");
      getchar();}
      break;
      case'5':
          {k=(FLIGHT*) fltlist;
          tuipiao(k);
          system("cls");
          getchar();}
          break;
      case'6':
          break;
      default;
          printf("没有这个选项！\n按回车键回主菜单。");
          getchar();
          system("cls");
          continue;}
        if(c=='6')
            break;}
 }
}}

[此贴子已经被作者于2018-7-4 00:40编辑过]

主函数好像没问题，是不是下面这个函数的问题
char chaxunhangban(FLIGHT *fltlist)
{
    char mn_szat[30];
    char mn_szto[30];
    FLIGHT *p;
    p=fltlist;
    int i;
    int j=0;
    int k;
    char c='y';
    while(c=='y'||c=='Y')
    {
        printf("请输入你的查询方式:\n1.按目的地.\n2.按路线查.");
        scanf("%d",&k);
        switch(k)
        {
case1:
        {
            printf("请输入起飞地:");
            scanf("%s",&mn_szat);
            for(i=0;i<M;i++)
            {
                if(strcmp((p+i*N)->m_szat,mn_szat)==0)
                {
                    j++;
                    printf("查询的航班号为:%d!\n",i);
                }
            }
            break;
        }
case2:
            {
                printf("请输入目的地:");
                scanf("%s",&mn_szto);
                for(i=0;i<M;i++)
                {
                    if(strcpy((p+i*N)->m_szto,mn_szto)==0)
                    {
                        j++;
                        printf("查询的航班号为:%d!\n",i);
                    }
                }
                break;
            }
case3:
                {
                    printf("你要查询本航班的以下信息吗？(y/n)\n");
                    goto loop;
               
        default:
            {
                printf("没有这个选项!按回车键退出查询系统");
                getchar();
            }
            break;
            }
            printf("\n你还要继续查询航班吗?(y/n)");
            getchar();
            scanf("%c",&c);
        }
        printf("你还要继续查询本航班更详细的信息吗？（具体如下）:\n");
loop:
        printf("\t\t\t\t   a.显示空座的数量\n");
        printf("\t\t\t\t   b.显示已订座信息\n");
        printf("\t\t\t\t   c.起飞时间\n");
        printf("请选择(y\n):");
        getchar();
        scanf("%c",&c);
        getchar();
        return(c);
    }