使用指针数组而不是二维数组时出错

如果我在这里给出了指针数组,下面的代码就会崩溃。有没有其他方法可以通过指针数组接受值,或者我在这里做错了什么

编译后运行此程序,您应该键入 objectname-行数

  //program to print first n lines of string using command  line arguement
#include<stdio.h>
#include<ctype.h>
#include<stdlib.h>
#include<string.h>
int less(int x,int y);`enter code here`
int main(int argc,char* argv[])
 {
     int i,j,n,num;
    char *lines[100];/*if I use two dimensional array here the code compiles
    char nu[6];

 // the whole for loop is for checking error in n
    for(i=1,n=strlen(argv[1]);i<n;i++)
    {
            if(argv[1][i]=='.')
            {
                    printf("your input was not correct \n");
                    return 0;
            }
            if(argv[1][i]=='-')
            {
                    printf("your input was not correct \n");
                    return 0;
            }
            if(isalpha(argv[1][i])!=0)
            {
                printf("your input was not correct indeed");
                return 0;
            }
    }
    printf("\t\t application to print number of last n lines \n\n\n");
    printf("enter the number of lines\n");
    scanf("%d",&n);
    printf("enter your lines \n");
    for(j=0;(n<100)&&(j<=n);j++)
    {
            gets(lines[j]);
    }
    strcpy(nu,argv[1]);
    nu[0]=' ';
    num=atoi(nu);
    num=(less(num,n));
    for(i=0;i<=num;i++)
    {
            printf("%s",lines[i]);
    }
    return 0;
}
int less(int x,int y)
{
    int z;
    return (z=(x>y?y,printf("your input lines are less\n"):x));
}