0917 Experimental One lexical analysis program

#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");p rintf ("Please enter source program: \ n"); (a); while (a[i]!= ') {j=0;if ((Isalpha (a[i))) | | (a[i]== ' _ ')) {while ((a[i]!= ') && (a[i]!= ')) {if ((Isalpha (a[i))) | | (IsDigit (A[i])))     {B[j]=a[i];     j + +; i++;} Elsebreak;} if ((a[i]== ') | | (a[i]== '))    {b[j]= ' + ';                if (strcmp (B,K[0].G) ==0) printf ("Begin\t species Code 1\n");    else if (strcmp (B,K[1].G) ==0) printf ("if \ T species code 2\n");    else if (strcmp (B,K[2].G) ==0) printf ("then \ T species code 3\n");    else if (strcmp (B,K[3].G) ==0) printf ("While\t species Code 4\n");    else if (strcmp (B,K[4].G) ==0) printf ("Do t \ Species code 5\n");    else if (strcmp (B,K[5].G) ==0) printf ("End \ T species code 6\n"); else printf ("%s \ T species code 10\n", b);}Else{b[j]= ';p rintf ("%s \ T species code 10\n", b); i--;}}     else if (IsDigit (A[i])) {J=0;while (IsDigit (A[i])) {b[j]=a[i];     j + +; i++;} B[j]= ';p rintf ("%s \ T species code 11\n", b); i--;} Else{switch (A[i]) {case ' + ':p rintf ("%c \ Species Code 13\n", A[i]); Break;case '-':p rintf ("%c \ T species code 14\n", A[i]); Break;case ' * ' :p rintf ("%c \ Species Code 15\n", A[i]), break;case '/':p rintf ("%c \ T species code 16\n", A[i]); Break;case ': ': if (a[i+1]== ' = ') {printf (": = \ t Species code 18\n "); i++;break;} else{printf ("%c \ T species code 17\n", A[i]); Case ' < ': if (a[i+1]== ' = ') {printf ("<= \ T species code 21\n"); i++;break;} if (a[i+1]== ' > ') {printf ("<> \ T species code 22\n"); i++;break;} else printf ("%c \ Species Code 20\n", A[i]); Break;case ' > ': if (a[i+1]== ' = ') {printf (">= \ T species code 24\n"); i++;break;}   else printf ("%c \ Species Code 23\n", A[i]), break;case ' = ':p rintf ("= \ t species code 25\n"); Break;case '; ':p rintf ("; \ t species code 26\n ") break;case ' (':p rintf (" (\ t species code 27\n); Break;case ') ':p rintf (") \ T species code 28\n"); Break;case ' # ':p rintf (  "# \ t species code 0\n "); break;default:printf ("%c \ t syntax error!\n ", A[i]); break;}}    i++;}}

　　

0917 Experimental One lexical analysis program