简易四则运算编译器（自己的创作 C语言）

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源程序

#include<stdio.h>

#include<math.h>

typedef struct word{

double v;

int c;

}word;

word B[10];

double result[10];

int s2=0;

void in(int c)

{ if(B[c].c==1)

{result[s2]=B[c].v;

s2++;}

else if(B[c].c<6){

result[s2]=B[c].c;

s2++;

}

void compute()

{ int s;

double m1,m2;

s2--;m2=result[s2];

s2--;s=(int)result[s2];

s2--;m1=result[s2];

switch(s){

case 2:result[s2]=m1+m2;s2++;break;

case 3:result[s2]=m1-m2;s2++;break;

case 4:result[s2]=m1*m2;s2++;break;

case 5:result[s2]=m1/m2;s2++;break;

}

int cifafenxi(int &s);

main()

{ int i,j,k,m,n;

int a,b,c,s,ci,s1;

int F[20],G[20];

typedef struct shi{

int x;

int y;

char z;

}shi;

shi D[11];

int C[16][14]={{0,5,0,0,0,0,4,0,0,1,2,3,0,0},

{0,0,7,8,0,0,0,0,40,0,0,0,6,0},

{0,0,22,22,10,11,0,22,22,0,0,0,0,9},

{0,0,24,24,24,24,0,24,24,0,0,0,0,0},

{0,5,0,0,0,0,4,0,0,12,2,3,0,0},

{0,0,26,26,26,26,0,26,26,0,0,0,0,0},

{0,5,0,0,0,0,4,0,0,0,13,3,0,0},

{0,27,0,0,0,0,27,0,0,0,0,0,0,0},

{0,28,0,0,0,0,28,0,0,0,0,0,0,0},

{0,5,0,0,0,0,4,0,0,0,0,14,0,0},

{0,29,0,0,0,0,29,0,0,0,0,0,0,0},

{0,30,0,0,0,0,30,0,0,0,0,0,0,0},

{0,0,7,8,0,0,0,15,0,0,0,0,6,0},

{0,0,21,21,10,11,0,21,21,0,0,0,0,9},

{0,0,23,23,23,23,0,23,23,0,0,0,0,0},

{0,0,25,25,25,25,0,25,25,0,0,0,0,0}};

j=1;m=9;

for(i=0;i<5;i++)

{ for(k=0;k<2;k++)

{ D[j].x=m;

j++;}

m++;};

for(i=1;i<=10;i++)

D[i].y=1;

D[1].y=D[3].y=D[5].y=3;

D[3].z=D[4].z='T';

D[1].z=D[2].z='E';

D[5].z=D[6].z='F';

D[7].z=D[8].z='A';

D[9].z=D[10].z='M';

ci=cifafenxi(s1);

if(!ci){printf("词法错误。/n");return(0);}

B[s1].c=8;

a=b=c=0;

F[0]=0;G[0]=8;

printf("状态栈");printf("/t");

printf("符号栈");printf("/t");

printf("余留串");printf("/t");

printf("动作");printf("/t");

printf("下一状态/n");

for(i=0;i<=a;i++)

printf("%d",F[i]);

printf("/t");printf("#");

for(i=1;i<=b;i++)

printf("%d",G[i]);

printf("/t");

for(i=c;B[i].c!=8;i++)

printf("%d",B[i].c);

printf("#");printf("/t");

while(C[F[a]][B[c].c]!=40)

{ if(a==b)

{ m=C[F[a]][B[c].c];

if(m<20)

{ a++;b++;

F[a]=m;

G[b]=B[c].c;

c++;

in(c-1);

if(m==0){

printf("错误语法。/n");return(0);}

}

else {s=n=m-20;

a=a-D[n].y;

b=b-D[n].y+1;

G[b]=D[n].x;

if(n==1||n==3)

compute();}

}

if(a!=b){n=C[F[a]][G[b]];

a++;

F[a]=n;}

if(m<20){printf("S%d",m);

printf("/t");

printf("%d/n",m);

}

else {printf("R%d",s);

printf("/t");

printf("Goto=%d/n",F[a]);

}

for(i=0;i<=a;i++)

printf("%d",F[i]);

printf("/t"); printf("#");

for(i=1;i<=b;i++){

if(G[i]>8)

switch(G[i]){

case 9: printf("%c",D[1].z);break;

case 10:printf("%c",D[3].z);break;

case 11:printf("%c",D[5].z);break;

case 12:printf("%c",D[7].z);break;

case 13:printf("%c",D[9].z);break;}

else printf("%d",G[i]);}

printf("/t");

for(i=c;B[i].c!=8;i++)

printf("%d",B[i].c);

printf("#");

printf("/t");

}

if(C[F[a]][8]==40){

printf("Acc 正确语法！/n");

printf("result=%f/n",result[0]);}

return(0);

}

int cifafenxi(int &s)

{

int i,p,e,n,j,r=0;

char A[20];

char a;

double sum=0,sum1=0,sum2=0,sum3,m=0,x=0;

i=p=e=s=n=j=0;

printf("请输入无符号数四则运算表达式：/n");

scanf("%s",&A);

printf("词法分析结果：/n");

a=A[0];

while(A[i]!='/0')

{

switch(A[i]){

case '+':printf("%c 类型码为 2/n",A[i]);B[s].c=2;

a=A[i+1];