词法分析

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#define Max 1000
int j=1;
long g=0;
char nchar[Max]={""}; 
int k=0;
char ch=NULL;
char m[30]={""};
main()
{
    char cha;
    int p;
    printf("请输入一串字符串:");
    while((cha=getchar())!='$')
    {
        nchar[g]=cha;
        g++;
    } 
    do
    {
        p=getsym();
    }while(p); 
}
int getsym()
{
    int i;
    char a[2]={""};
    char word[][15]={"begin","do","end","if","then","while"};
    int wsym[6]={1,2,3,4,5,6};
    int ssym[9]={25,26,27,28,0,13,14,15,16};
    char b[9]={'=',';','(',')','#','+','-','*','/'};
    if(j==1&&k<g)
    {
        ch=nchar[k];
        j++;
        k++;
    }
    while(ch==' '||ch==10||ch==9||ch==13)
    {
        if(k==g)
        {
            return 0;
        }
        ch=nchar[k];
        k++;
    }
    if(ch>='a'&&ch<='z')
    {
        while((ch>='a'&&ch<='z')||(ch>='0'&&ch<='9')||ch=='_')
        {
            a[0]=ch;
            strcat(m,a);
            if(k==g)
            {
                break;
            }
            ch=nchar[k];
            k++;
        }
        for(i=0;i<12;i++)
        {
            if(strcmp(m,&word[i][0])==0)
                break;
        }
        if(i<12)
        {
            sym=wsym[i]; 
            printf("保留字%s  种别码%d\n",m,wsym[i]);
        }
        else
        {
            sym=11;
            printf("标识符%s  种别码11\n",m);
        }
        if(k==g)
        return 0;
        strcpy(m,"");
        return 1;
    }
    else if(ch>='0'&&ch<='9')
    {
        while(ch>='0'&&ch<='9')
        {
            a[0]=ch;
            strcat(m,a);
            if(k==g)
            {
                break;
            }
            ch=nchar[k];
            k++;
        }

部分代码