the blog of devil

#include<iostream>
using namespace std;
char prog[1000], s, token[8];
int p = 0, syn = 0, n, m, sum, row;
char *key[8] = { "if","then","else","end","repeat","until","read","write" };
void f()
{
    for (int i = 0; i < 8; i++) token[i] = NULL;
    s = prog[p++];
    while (s == ' ')
    {
        s = prog[p];
        p++;
    }
    if ((s >= 'a'&&s <= 'z') || (s >= 'A'&&s <= 'Z'))  //首先判断是否为标识符
    {
        m = 0;
        while ((s >= '0'&&s <= '9') || (s >= 'a'&&s <= 'z') || (s >= 'A'&&s <= 'Z'))
        {
            token[m++] = s;
            s = prog[p++];
        }
        token[m++] = '