1 #include<stdio.h>  2 #include<malloc.h>   3 #include<stdlib.h>  4 #include<ctype.h>  5 typedef struct node  6 {  7     char ch;  8     struct node *next;  9 }QNode,*QueuePtr; 10  11 typedef struct 12 { 13     QueuePtr front; 14     QueuePtr rear; 15 }LinkQueue; 16  17 LinkQueue Q; 18 QueuePtr p;        //定义一个指针变量  19 char *keyword[30]={"main","scanf","printf","void","int","float","double","char","long","short","signed", 20                "struct","do","while","for","switch","case","break","continue","if","define","typedef","union", 21                 "static","sizeof","return","extern","goto","auto","const"}; 22 char *operatornum[6]={"+","-","*","/","++","--"};   23 char *comparison[8]={"<","<=","=",">",">=","<>","==","!="};   24 char *interpunction[8]={",",";",":=",".","(",")","{","}"};   25 char *biaoshifu[6]={"%","$","^","&","_","#"};   //特殊标识符   26 char *zhushifu[3]={"//","/*","*/"};          //注释符   27 char *luoji[3]={"&&","||","!"};             //逻辑运算符   28 char *k=""; 29  30 void InitQueue()      //初始化一个带节点的空队列  31 { 32     Q.front=Q.rear=(QueuePtr)malloc(sizeof(QNode)); 33     if(!Q.front)    34       exit(0); 35     Q.front->next=NULL; 36 } 37 void Printf() 38 { 39     QueuePtr p;        //定义一个指针变量  40     p=Q.front; 41     while(!(p==Q.rear)) 42     { 43         p=p->next; 44         printf("%c",p->ch); 45     } 46     printf("\n"); 47 } 48 void Creat()    //创建队列  49 { 50     char ch; 51     QueuePtr p; 52     printf("请输入您要分析的字符串"); 53     ch=getchar(); 54     while(ch!=‘@‘) 55     { 56         p=(QueuePtr)malloc(sizeof(QNode)); 57         p->ch=ch; 58         p->next=NULL; 59         Q.rear->next=p; 60         Q.rear=p; 61         ch=getchar(); 62     } 63 } 64  65  66 int search(char searchstr[],int wordtype)//符号匹配    67 {   68     int i;   69     switch (wordtype)   70     {   71         case 1:   72                printf("你好"); 73             for(i=0;i<30;i++)   74             {   75                 if(strcmp(keyword[i],searchstr)==0)   76                 return i;   77             }   78             break;   79         case 2:   80             for(i=0;i<=5;i++)   81             {   82                 if(strcmp(operatornum[i],searchstr)==0)   83                 return 30+i;   84             }   85          break;   86                87         case 3:    88             for(i=0;i<=7;i++)   89             {   90              if(strcmp(comparison[i],searchstr)==0)   91                 return 36+i;   92             }   93             break;   94       95         case 4:    96             for(i=0;i<=7;i++)   97             {   98                 if(strcmp(interpunction[i],searchstr)==0)   99                 return 44+i;  100             }  101     102             break;  103         case 5:   104             for(i=0;i<=5;i++)  105             {  106                 if(strcmp(biaoshifu[i],searchstr)==0)  107                     return 52+i;  108             }  109             break;  110         case 6:  111              for(i=0;i<=2;i++)  112              {  113                 if(strcmp(zhushifu[i],searchstr)==0)  114                     return 58+i;  115             }  116             break;  117         case 7:   118             for(i=0;i<=2;i++)  119             {  120                 if(strcmp(luoji[i],searchstr)==0)  121                     return 61+i;  122             }  123         break;  124     }  125   126     return 0;  127 }  128 void Analyze()129 {130     char str;131     char letter[20];  132     char num[20];  133     char other[20];  134     int i;135     p=Q.front;136     while(p!=Q.rear)       137     {138         139         p=p->next;        //获取单个字符 140         str=p->ch;141         if (isalpha(str)!=0)        //如果是字符 142         {143             i=-1;144            while (isalnum(str)!=0)  145           {  146             letter[++i]=str;  147             str=p->next->ch;  148           }  149            letter[i+1]=‘\0‘;  150            if (search(letter,1))  151           {  152             printf("( %d,%s )",search(letter,1),letter);  153             154           }  155           else  156           {  157               printf("( %d,%s )\n",65,letter);   158            }  159         }    160         else  161         {  162             if (isdigit(str)!=0)  163             {164                 i=-1;165                 while (isdigit(str)!=0)  166                 {  167                    num[++i]=str;  168                    str=p->next->ch; 169                 }  170                 if(isalpha(str)!=0)         //数字后面是字符   171                 {  172                     while(isspace(str)==0)  173                    {  174                      num[++i]=str;  175                      str=p->next->ch; 176                     }  177                    num[i+1]=‘\0‘;  178                    printf("错误！非法标识符：%s\n",num);  179                 180                 }  181                 num[i+1]=‘\0‘;  182                 printf("( %d,%s )",64,num);  183             }184             else  185             {186               i=-1;    187               if (isspace(str)!=0)  188               {  189                  str=p->next->ch;190                  191               }  192               while ((isspace(str)==0)&&(isalnum(str)==0))  193               {  194                  other[++i]=str;  195                  str=p->next->ch; 196                }  197                   other[i+1]=‘\0‘;  198               if (search(other,2))  199                   printf("( %d,%s )\n",search(other,2),other);  200               else if (search(other,3))  201                   printf("( %d,%s )\n",search(other,3),other);  202               else if (search(other,4))  203                   printf("( %d,%s )\n",search(other,4),other);  204               else if (search(other,5))  205                   printf("( %d,%s )\n",search(other,5),other);  206               else if (search(other,6))  207                   printf("（ %s,注释符号 ）\n",other);  208               else if (search(other,7))  209                   printf("( %d,%s )\n",search(other,7),other);  210               else   211                   printf("错误！非法字符：%s\n",other);  212             }213         }  214     };  215      printf("词法分析结束，谢谢使用！\n"); 216 }217 218 int main()219 {220     221     InitQueue();    //创建空链队列 222     Creat();        //创建队列 223     Printf();       //输出队列 224     Analyze();      //词法分析 225     return 0;226 }