c - C 导航，无法编译

Question

作为学校项目的一部分，我必须构建一个程序，让用户穿过房子的房间。我是 C 新手，所以我有点卡在一个我无法解决的错误上。

该程序背后的概念是用户将通过带有数字的控制台输入方向命令，数字表示北，南，东，西的方向。

这是我的代码：

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

#define North 0
#define East 1
#define South 2
#define West 3

typedef struct{
    char Description[200];
    unsigned int Exit[4];
}
location;

void SetupRooms();
void DescribeRoom(unsigned int RoomNumber);
void DescribeExits(unsigned int RoomNumber);
int GetDirection(unsigned int RoomNumber);

location Room[8]; 

void main(){
    unsigned int RoomNumber=1;
    signed int Direction;
    SetupRooms();

    while(1){
        //system("cls");
        DescribeRoom(RoomNumber);
        DescribeExits(RoomNumber);
        Direction = GetDirection(RoomNumber);
        if(Direction ==-1)
        {
            printf("\n BYE BYE!\n");
            break;//exit(0);
        }
        if(Direction > 0) 
            RoomNumber = Direction;
        else 
            printf("\n You just walked into a wall! \n");
    }
}

void SetupRooms()
{
    strcpy(Room[1].Description,"Hallway. ");
    Room[1].Exit[North] =5;
    Room[1].Exit[East]  =7;
    Room[1].Exit[South] =-1;
    Room[1].Exit[West]  =2;

    strcpy(Room[2].Description,"Dining Room. ");
    Room[2].Exit[North]=4;
    Room[2].Exit[East]=1;
    Room[2].Exit[South]=0;
    Room[2].Exit[West]=3;

    strcpy(Room[3].Description, "Kitchen. ");
    Room[3].Exit[North]=-1;
    Room[3].Exit[East]=2;
    Room[3].Exit[South]=0;
    Room[3].Exit[West]=0;

    strcpy(Room[4].Description, "Main Bedroom. ");
    Room[4].Exit[North] =0;
    Room[4].Exit[East]=5;
    Room[4].Exit[South]=2;
    Room[4].Exit[West]=-1;

    strcpy(Room[5].Description, "Bathroom. ");
    Room[5].Exit[North]=0;
    Room[5].Exit[East]=6;
    Room[5].Exit[South]=1;
    Room[5].Exit[West]=4;

    strcpy(Room[6].Description, "Kids Bedroom. ");
    Room[6].Exit[North]=0;
    Room[6].Exit[East]=0;
    Room[6].Exit[South]=7;
    Room[6].Exit[West]=5;

    strcpy(Room[7].Description, "Lounge. ");
    Room[7].Exit[North]=6;
    Room[7].Exit[East]=-1;
    Room[7].Exit[South]=0;
    Room[7].Exit[West]=1 ;

}

void DescribeRoom(unsigned int RoomNumber)
{
    printf("The room you are in is the: %s",Room[RoomNumber].Description);
}

void DescribeExits(unsigned int RoomNumber)
{
    if (Room[RoomNumber].Exit[North] != -1)
        printf("To the North is the: %d",Room[RoomNumber].Exit[North]);

    else 
        printf("No Exit to the North");


    if (Room[RoomNumber].Exit[East] != -1)
        printf("To the East is the: %d",Room[RoomNumber].Exit[East]);

    else 
        printf("No Exit to the East");


    if (Room[RoomNumber].Exit[South] != -1)
        printf("To the South is the: %d",Room[RoomNumber].Exit[South]);

    else 
        printf("No Exit to the South");


    if (Room[RoomNumber].Exit[West] != -1)
        printf("To the West is the: %d",Room[RoomNumber].Exit[West]);

    else 
        printf("No Exit to the West");

}

int GetDirection(unsigned int RoomNumber)
{
    int RetVal = -1;
    char Input = _getch();
    switch(Input)
    {
    case 'n':
        RetVal = 0;
        break;
    case 's':
        RetVal = 1;
        break;
    case 'e':
        RetVal = 2;
        break;
    case 'w':
        RetVal = 3;
        break;
    }
    return RetVal;
}

这是我运行后得到的错误

;============ Building Project hose2 ============
;============ Linking ============
    Linker Error (Severity 4)
    No matching files for file specification:
    "|:\\acfs5\dt11\dt11ddf\my documents\cc386 projects\assign.prac.2.obj"
    Error: Unresolved External "_main" in Module "C:\tools\cc\clibs\platform\WIN32\pe\c0.c"
    Linker Error (Severity 255)
    Trouble opening "|:\\acfs5\dt11\dt11ddf\my documents\cc386 projects\hose2.lss" for output.
    Compile done.  Errors: 3,  Warnings: 0

Answer 1

Error: Unresolved External "_main" in ...

means the linker can't find the symbol called "_main" it was looking for. The main function is supposed to look like this:

int main() { ... }

or, if you need command-line arguments, like this:

int main(int argc, char *argv[]) { ... }

For future reference, you'll get a better response if you show you tried to narrow down the problem - here you could have removed all your code apart from void main() {} and still seen the same error. That would have been a pretty strong clue.

Answer 2

您的 main 函数需要返回一个整数（非零被解释为错误）。