#include <stdio.h>
#include <string.h>
#include <ctype.h>
typedef struct node
{
char list[81];
int tempi;
}sentance;//分离出一个个关键字所用临时结构
void printch(char stack[][10],int top);
int main()
{
sentance one,two,three;
char whole[800];//存放用户输入数据
char word=NULL;
char stack[800][10];//存放关键字以及变量的栈
int top=-1;
int i=1;
one.tempi=two.tempi=three.tempi=0;
printf("Please input the code and end with the '#':");
while(word!='#')
{
i=1;
gets(whole);
word=whole[0];//将字符串第一个字符赋给word
while(word!='#')
{
while(ispunct(word)&&(word!='#'))
{
two.list[two.tempi]=word;
two.tempi++;
word=whole[i];//i是以1开始，所以whole[i]是下一个字符
i++;
if(two.list[two.tempi-1]!=':'&&two.list[two.tempi-1]!='<'&&two.list[two.tempi-1]!='>')//若果不是这三个符号，则直接入栈
{
two.list[two.tempi]=' ';
top++;
strcpy(stack[top],two.list);
two.tempi=0;
}
else if(word=='='&&two.list[two.tempi-1]==':'||word=='='&&two.list[two.tempi-1]=='<'||word=='='&&two.list[two.tempi- 1]=='>'||word=='>'&&two.list[two.tempi-1]=='<')//比较是否为双标点情况
{
two.list[two.tempi]=word;
two.list[two.tempi+1]=' ';
top++;
strcpy(stack[top],two.list);
two.tempi=0;
word=whole[i];//将下一个字符赋给word
i++;//i指向下一个字符
}
else//当下一个字符没有组成双标点，则入栈
{
two.list[two.tempi]=' ';
top++;
strcpy(stack[top],two.list);
two.tempi=0;
}
}
while(isalpha(word)&&(word!='#'))
{
one.list[one.tempi]=word;
one.tempi++;
word=whole[i];
i++;
if(!(isalpha(word)))
{
one.list[one.tempi]=' ';
top++;
strcpy(stack[top],one.list);
one.tempi=0;
}
}
while(isdigit(word))
{
three.list[three.tempi]=word;
three.tempi++;
word=whole[i];
i++;
if(!(isdigit(word)))
{
three.list[three.tempi]=' ';
top++;
strcpy(stack[top],three.list);
three.tempi=0;
}
}
if(word==' ')//忽略空格
{
word=whole[i];
i++;
}
if(word==' ')//遇到结束符跳出循环
break;
}
}
if(top!=-1)//如果栈里无元素，则函数结束
printch(stack,top);
return 0;
}
void printch(char stack[][10],int top)
{
char clist[][6]={"begin","if","then","while","do","end","","","","","","","+","-","*","/",":",":=","","<","<=","<>",">",">=","=",";","(",")","#"};
int i,k;
for(k=0;k<=top;k++)
{
if(strlen(stack[k])!=0)
{
if(stack[k][0]>='0'&&stack[k][0]<='9')//数字的输出
{
printf("<11,"%s">
",stack[k]);
continue;//如果是数字则continue循环
}
for(i=0;i<=28;i++)
{
if(strcmp(clist[i],stack[k])==0)
{
printf("<%d,"%s">
",i+1,stack[k]);//关键字的输出
break;
}
if(i==28)//找不到相同的字符串，则作为一个变量输出
{
printf("<10,"%s">
",stack[k]);
}
}
}
}
}