编译原理 预测分析 源代码c 语言

#include
#include
#include
#include
char A[20];//分析栈 
char B[20];//剩余串 
char v1[20] = { 'i','+','*','(',')','#' };//终结符
char v2[20] = { 'E','G','T','S','F' };//非终结符
int j = 0, b = 0, top = 0, l;//L为输入串长度
typedef struct type//产生式类型定义
{ 
char origin;//大写字符
char array[5];//产生式右边字符 
int length;//字符个数
}type; 
type  e, t, g, g1, s, s1, f, f1;//结构体变量
type  C[10][10];//预测分析表
void  print()//输出分析栈
{  
int a;//指针 
for (a = 0; a <= top + 1; a++)
printf("%c", A[a]);
printf("\t\t");
}/*print*/ 
void  print1()/*输出剩余串*/ 
{  
int j; 
for (j = 0; j printf(" "); 
for (j = b; j <= l; j++) 
printf("%c", B[j]); 
printf("\t\t\t");  }/*print1*/ 
void  main()  
{  
int  m, n, k = 0, flag = 0, finish = 0; 
char  ch, x; 
type  cha;/*用来接受C[m][n]*/ /*把文法产生式赋值结构体*/ 
e.origin = 'E';
strcpy(e.array, "TG"); 
e.length = 2; 
t.origin = 'T'; 
strcpy(t.array, "FS"); 
t.length = 2; 
g.origin = 'G'; 
strcpy(g.array, "+TG"); 
g.length = 3; 
g1.origin = 'G'; 
g1.array[0] = '^'; 
g1.length = 1; 
s.origin = 'S'; 
strcpy(s.array, "*FS"); 
s.length = 3; 
s1.origin = 'S'; 
s1.array[0] = '^'; 
s1.length = 1; 
f.origin = 'F'; 
strcpy(f.array, "(E)"); 
f.length = 3; 
f1.origin = 'F';
f1.array[0] = 'i'; 
f1.length = 1; 

for (m = 0; m <= 4; m++)/*初始化分析表*/ 
for (n = 0; n <= 5; n++) 

C[m][n].origin = 'N';/*全部赋为空*/ 
/*填充分析表*/ 
C[0][0] = e; C[0][3] = e; 
C[1][1] = g; C[1][4] = g1; C[1][5] = g1; 
C[2][0] = t; C[2][3] = t; 
C[3][1] = s1; C[3][2] = s; C[3][4] = C[3][5] = s1; 
C[4][0] = f1; C[4][3] = f; 
printf("提示:本程序只能对由'i','+','*','(',')'构成的以'#'结束的字符串进行分析,\n"); 
printf("请输入要分析的字符串:"); 
do/*读入分析串*/
{
scanf("%c", &ch); 
if ((ch != 'i')  && (ch != '+')  && (ch != '*') && (ch != '(') && (ch != ')') && (ch != '#')) 
{
printf("输入串中有非法字符\n");
exit(1); 
}B[j] = ch; 
j++; 
}while (ch != '#');
l = j;/*分析串长度*/ 
ch = B[0];/*当前分析字符*/ 
A[top] = '#'; 
A[++top] = 'E';/*'#','E'进栈*/ 
printf("步骤\t\t分析栈\t\t剩余字符\t\t所用产生式\n"); 
do { 
x = A[top--];/*x为当前栈顶字符*/ 
printf("%d", k++); 
printf("\t\t"); 
for (j = 0; j <= 5; j++)/*判断是否为终结符*/
if (x == v1[j]) 
{ 
flag = 1; 
break;  } 
if (flag == 1)/*如果是终结符*/ 
{ 
if (x == '#') 
{ 
finish = 1;/*结束标记*/ 
printf("acc!\n");/*接受?*/ 
getchar(); 
getchar(); 
exit(1); 
 }/*if*/
if (x == ch) 
{ 
print(); 
print1(); 
printf("%c匹配\n", ch); 
 ch = B[++b];/*下一个输入字符*/ 
flag = 0;/*恢复标记*/ }/*if*/ 
else/*出错处理*/  
{ print();  print1(); 
 printf("%c出错\n", ch);/*输出出错终结符*/ 
exit(1); }/*else*/ 

}/*if*/
else/*非终结符处理*/
{
for (j = 0; j <= 4; j++) 
if (x == v2[j]) 
{ 
m = j;/*行号*/ 
break; 
 } 
 for (j = 0; j <= 5; j++) 
if (ch == v1[j])
{ n = j;/*列号*/  break; 
} 
 cha = C[m][n]; 
 if (cha.origin != 'N')/*判断是否为空*/ 
 {  print();
 print1(); 
 printf("%c->", cha.origin);/*输出产生式*/ 


for (j = 0; j printf("%c", cha.array[j]);
printf("\n");
for (j = (cha.length - 1); j >= 0; j--)/*产生式逆序入栈*/ 
A[++top] = cha.array[j];
if (A[top] == '^')/*为空则不进栈*/ 
top--; 
}/*if*/ 
else/*出错处理*/  {  print(); 
print1(); 
printf("%c出错\n", x);/*输出出错非终结符*/ 

exit(1); 
}/*else*/ 

}/*else*/ 

 }while (finish == 0);  }/*main*/