#include<stdio.h>
#include<string.h>#include<ctype.h>#define M 1000struct key{ char g[20];};typedef struct key KEY;int main(){ KEY k[6]; int i=0,j=0; char a[M],b[M]; strcpy(k[0].g,"begin"); strcpy(k[1].g,"if"); strcpy(k[2].g,"then"); strcpy(k[3].g,"while"); strcpy(k[4].g,"do"); strcpy(k[5].g,"end"); printf("请输入源程序:
"); gets(a); while(a[i]!=' ') { j=0; if((isalpha(a[i]))) { while((a[i]!=' ')) { if((isalpha(a[i]))) { b[j]=a[i]; j++; i++; } else break; } if((a[i]==' ')) { b[j]=' '; if(strcmp(b,k[0].g)==0) printf("begin 种别码 1
"); else if(strcmp(b,k[1].g)==0) printf("if 种别码 2
"); else if(strcmp(b,k[2].g)==0) printf("then 种别码 3
"); else if(strcmp(b,k[3].g)==0) printf("while 种别码 4
"); else if(strcmp(b,k[4].g)==0) printf("do 种别码 5
"); else if(strcmp(b,k[5].g)==0) printf("end 种别码 6
"); else printf("%s 种别码 10
",b); } else { b[j]=' '; printf("%s 种别码 10
",b); i--; } } else if(isdigit(a[i])) { j=0; while(isdigit(a[i])) { b[j]=a[i]; j++; i++; } b[j]=' '; printf("%s 种别码 11
",b); i--; } else { switch(a[i]) { case '+': printf("%c 种别码 13
",a[i]);break; case '-': printf("%c 种别码 14
",a[i]);break; case '*': printf("%c 种别码 15
",a[i]);break; case '/': printf("%c 种别码 16
",a[i]);break; case ':': if(a[i+1]=='=') { printf(":= 种别码 18
");i++;break;} else { printf("%c 种别码 17
",a[i]);break;} case '<': if(a[i+1]=='=') { printf("<= 种别码 21
");i++;break;} if(a[i+1]=='>') { printf("<> 种别码 22
");i++;break;} else printf("%c 种别码 20
",a[i]);break; case '>': if(a[i+1]=='=') { printf(">= 种别码 24
");i++;break;} else printf("%c 种别码 23
",a[i]);break; case '=': printf("= 种别码 25
");break; case ';': printf("; 种别码 26
");break; case '(': printf("( 种别码 27
");break; case ')': printf(") 种别码 28
");break; case '#': printf("# 种别码 0
");break;
} } i++; } return 0;
}