#include<stdio.h>
#include<string.h>
int location=0;			//遍历字符串的当前位置
char arr[20]="id+id*id#";
void error();		//错误提示函数
/*
每一个非终结符都构造一个函数
*/
void E(char t);			
void Ep(char t);
void T(char t);
void Tp(char t);
void F(char t);void E(char t){if(t=='('){printf("E->TE'");printf("\n");T(arr[location]);Ep(arr[location]);}else if(t=='i'){printf("E->TE'");printf("\n");T(arr[location]);Ep(arr[location]);}else{error();location++;E(arr[location]);}
}
void T(char t){if(t=='i'){printf("T->FT'");printf("\n");F(arr[location]);Tp(arr[location]);}else if(t=='('){printf("T->FT'");printf("\n");F(arr[location]);Tp(arr[location]);}else{error();location++;T(arr[location]);}
}
void Ep(char t){if(t=='+'){printf("E'->+TE'");printf("\n");location++;T(arr[location]);Ep(arr[location]);}else if(t==')'){printf("E'->&");printf("\n");}else if(t=='#'){}else{error();if(t=='i')location+=2;elselocation++;Ep(arr[location]);}
}
void Tp(char t){switch(t){case '+':printf("T'->&");printf("\n");break;case '*':printf("T'->*FT'");printf("\n");location++;F(arr[location]);Tp(arr[location]);break;case ')':printf("T'->&");printf("\n");break;case '#':printf("T'->&");printf("\n");break;default:error();if(t=='i')location+=2;elselocation++;Tp(arr[location]);break;}
}
void F(char t){if(t=='i'){printf("F->id");printf("\n");location+=2;}else if(t=='('){printf("F->(E)");printf("\n");}else{error();location++;F(arr[location]);}
}
void error(){printf("有一个错误，略过当前词法记号");printf("\n");
}
int main(){E(arr[location]);
}

运行结果：