这个代码哪里错了啊？为什么Visual c++6.0

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX_LINE 1024
char* substr(char *s,int startPos,int endPos){
char t[endPos-startPos];
strncpy(t, s + startPos, endPos);
t[endPos] = '\0';
printf("%s\n", t);
return t;
}
int index(char *a,char c)
{
//printf("index yunx");
int i=0;
while(a[i]!='\0')
{
if(a[i]==c)
break;
i++;
}
return i;
}
int main()
{
char buf[MAX_LINE]; /缓冲区/
FILE *fp; /文件指针/
int len; /行字符个数/
if((fp = fopen("word.txt","r")) == NULL)
{
perror("fail to read");
exit (1) ;
}
//FILE *fpWrite=fopen("newtest.txt","w");
//if(fpWrite==NULL)
//{ return 0; }
char wordArray[100][MAX_LINE];
int i=0,j=0;
while(fgets(buf,MAX_LINE,fp) != NULL)
{
len = strlen(buf);
j=len;
buf[len-1] ='\0'; /去掉换行符/
printf("%s\n",buf);
strcpy(wordArray[i],buf);
i++;
}
printf("in put your want to memory word number:\n");
int memoryWordNumber;
scanf("%d",&memoryWordNumber);
char sutinputword[50];
int wordLength,intindexO;
for(int j=0;j<memoryWordNumber;j++)
{
i = rand() % 10; //产生0~9的随机数，注意10会被整除
char a[50];
strcpy(a,wordArray[i]);
intindexO=index(a,' ');//取空格的位置。如apple 苹果 位置为6
len=strlen(wordArray[i]);
printf("in put the word %s\n",substr(wordArray[i],intindexO,len));
scanf("%s",sutinputword);
if(strcmp(sutinputword,substr(wordArray[i],0,intindexO))==0)//比较学生输入的与word里面的是否相等
printf("right!");
else printf("wrong");
}
return 0;
}

测试没问题, 你是不是文件没放对
你在D盘建一个 t.txt 文件试试这个代码

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX_LINE 1024
char* substr(char *s,int startPos,int endPos)
{
    char t[endPos-startPos];
    strncpy(t, s + startPos, endPos);
    t[endPos] = '\0';
    printf("%s\n", t);
    return t;
}
int index(char *a,char c)
{
//printf("index yunx");
    int i=0;
    while(a[i]!='\0')
    {
        if(a[i]==c)
            break;
        i++;
    }
    return i;
}
int main()
{
    char buf[MAX_LINE];
    //缓冲区/
    FILE *fp;
    //文件指针/
    int len;
    //行字符个数/
    if((fp = fopen("D:\\t.txt","r")) == NULL)
    {
        perror("fail to read");
        exit (1) ;
    }
//FILE *fpWrite=fopen("newtest.txt","w");
//if(fpWrite==NULL)
//{ return 0; }
    char wordArray[100][MAX_LINE];
    int i=0,j=0;
    while(fgets(buf,MAX_LINE,fp) != NULL)
    {
        len = strlen(buf);
        j=len;
        buf[len-1] ='\0';
        //去掉换行符/
        printf("%s\n",buf);
        strcpy(wordArray[i],buf);
        i++;
    }
    printf("in put your want to memory word number:\n");
    int memoryWordNumber;
    scanf("%d",&memoryWordNumber);
    char sutinputword[50];
    int wordLength,intindexO;
    for(int j=0; j<memoryWordNumber; j++)
    {
        i = rand() % 10; //产生0~9的随机数，注意10会被整除
        char a[50];
        strcpy(a,wordArray[i]);
        intindexO=index(a,' ');//取空格的位置。如apple 苹果 位置为6
        len=strlen(wordArray[i]);
        printf("in put the word %s\n",substr(wordArray[i],intindexO,len));
        scanf("%s",sutinputword);
        if(strcmp(sutinputword,substr(wordArray[i],0,intindexO))==0)//比较学生输入的与word里面的是否相等
            printf("right!");
        else printf("wrong");
    }
    return 0;
}