#include<stdio.h>#include<string.h>#define N 30char str[N]={NULL},st[N]={NULL};int t=0,t1=0;struct node//定义一个队列{    char data;    struct node * next;};typedef struct node QueueNode;struct node2//定义一个链队列{    QueueNode *front;    QueueNode *rear;};typedef struct node2 Queue;void Print(char str[]);void Print1(char str1[]);Queue InitQueue()//初始化队列{    Queue Q;    Q.front=(QueueNode *)malloc(sizeof(QueueNode));    Q.front->next=NULL;    Q.rear=Q.front;    return(Q);}Queue InserQ(Queue Q,char x)//x进队列{    QueueNode *p;    p=(QueueNode *)malloc(sizeof(QueueNode));    p->data=http://www.mamicode.com/x;    p->next=NULL;    Q.rear->next=p;    Q.rear=p;    return(Q);}Queue DeleteQ(Queue Q)//出队列{    int i=t++,j;    QueueNode *p;    char y=NULL;    if(Q.front==Q.rear)    {        printf("队列为，无法出队列！");//判断队列是否为空        return(Q);    }    p=Q.front->next;    y=Q.front->next->data;//将队列中的元素赋值给y    Q.front->next=p->next;    if(p==Q.rear)        Q.rear=Q.front;    if((y>=‘A‘&&y<=‘Z‘)||(y>=‘a‘&&y<=‘z‘))//利用ASCII判断y是否是属于字母，并存储在数组str中        str[i]=y;    else    {        if(str[0]!=NULL)//如果数组str非空，则输出            Print(str);        t=0;        if(y==‘+‘||y==‘-‘||y==‘*‘||y==‘/‘||y==‘:‘||y==‘<‘||y==‘>‘)//判断字符是否是运算符        {            if(p->next->data=http://www.mamicode.com/=‘=‘)//判断运算是否是由两个字符组成            {                printf("（运算符，%c%c）\n",y,p->next->data);                Q.front->next=p->next->next;                free(p->next);            }            else                printf("（运算符，%c）\n",y);        }        else if(y==‘=‘)//判断字符是否是运算符            printf("（运算符，%c）\n",y);        else if(y>=48&&y<=57)//判断字符是否为数字        {            j=t1++;            st[j]=y;//将字符数字赋值给数组st            if(p->next->data<48||p->next->data>57)//判断队列中下一个字符是否为数字，如果是非字符数字，则输出数组st                if(st[0]!=‘\o‘)                {                     printf("（常数，%s）\n",st);                     memset(st,0,N);//清空数组str里的所有元素                     t1=0;                }        }        else if(y==33||y==34||(y>=39&&y<=41)||y==44||y==46||y==58||y==59||(y>=91&&y<=96)||(y>=123&&y<=125))//判断是否为界符            printf("（界符，%c）\n",y);        else if(y==‘ ‘)            printf("（空格符，%c）\n",y);//判断空格符        else            printf("（特殊符号，%c）\n",y);//其他的当作特殊符号处理    }    free(p);    return Q;}int main(){    char x,y;    Queue p,q;    p=InitQueue();    printf("请输入你想输入的字母、单词、短语、句子、字符等(必须以非数字结尾，否则程序出错)：\n");    while(scanf("%c",&x)==1&&x!=‘\n‘)//大神的方法，牛        p=InserQ(p,x);    q=p;    while(p.front!=p.rear)        p=DeleteQ(p);    if(str[0]!=‘\o‘)//判断数组str是否为空        Print(str);}void Print(char str[])//调用函数来判断关键字与标识符{    int i=0;    if(strcmp(str,"break")==0||strcmp(str,"case")==0||strcmp(str,"char")==0||strcmp(str,"const")==0||strcmp(str,"continue")==0||strcmp(str,"default")==0||strcmp(str,"do")==0||strcmp(str,"double")==0||strcmp(str,"else")==0||strcmp(str,"enum")==0||strcmp(str,"extern")==0||strcmp(str,"float")==0||strcmp(str,"for")==0||strcmp(str,"goto")==0||strcmp(str,"if")==0||strcmp(str,"int")==0||strcmp(str,"long")==0||strcmp(str,"register")==0||strcmp(str,"return")==0||strcmp(str,"short")==0||strcmp(str,"signed")==0||strcmp(str,"sizeof")==0||strcmp(str,"static")==0||strcmp(str,"struct")==0||strcmp(str,"switch")==0||strcmp(str,"typedef")==0||strcmp(str,"unsigned")==0||strcmp(str,"union")==0||strcmp(str,"void")==0||strcmp(str,"volatile")==0||strcmp(str,"while")==0||strcmp(str,"auto")==0)        printf("（关键字，%s）\n",str);    else    {        if(str[0]==‘\0‘)            return;        printf("（标识符，%s）\n",str);    }    memset(str,0,N);//清空数组str里的所有元素}