1 #include"stdio.h"
 2 #include"string.h"
 3 #define address "jisuanqi.txt"
 4 
 5 char stack[200];
 6 int out[200];
 7 int k=0,t=0;
 8 
 9 void up(int a,int b,char flag)
10 {
11     int q;
12     if(flag=='*'){
13         q=a*b;
14         out[k]=q;
15         k++;
16     }
17     else{
18         q=a/b;
19         out[k]=q;
20         k++;
21     }
22 }
23 
24 void result()
25 {
26     int len1=strlen(stack)-1,len2=strlen(out)-1;
27     while(len2>=0)
28     {
29         if(stack[len1]=='+')out[len2]=out[len2+1]+out[len2];
30         else out[len2]=out[len2]-out[len2+1];
31         len2-=1;
32         stack[len1]=NULL;
33         len1--;
34     }
35     printf("%d",out[0]);
36 }
37 
38 void translate(char str[])
39 {
40     stack[0]='1';
41     char ch,flag;
42     int i=0,l=0,j=0;
43     int a,b;
44 
45     ch=str[i];
46 
47     while(ch!='\0')
48     {
49         switch(ch){
50             case '-':
51             case '+':
52                 for(l;l<strlen(stack);l++)
53                     if(stack[l]=='*'||stack[l]=='/')break;
54                     flag=stack[l];
55                     stack[l]=ch;
56                     k=k-2;
57                     a=out[k];b=out[k+1];
58                     out[k]=NULL;
59 
60                     up(a,b,flag);
61                     break;
62             case '*':
63             case '/':
64                 stack[t]=ch;t++;
65                 break;
66             default:
67                 j=0;
68                 while(ch>='0'&&ch<='9'){
69                     j=j*10+(ch-'0');
70                     i++;
71                     ch=str[i];
72                 }
73                 i--;
74                 out[k]=j;k++;
75                 break;
76         }
77         i++;
78         ch=str[i];
79     }
80 }
81 
82 int main()
83 {
84     FILE *fp;
85     char str[200];
86     fp=fopen(address,"w");
87     printf("please input a string:\n");
88     gets(str);
89     fputs(str,fp);
90     translate(str);
91     result();
92     fputc('=',fp);
93     fputc(out[0],fp);
94     fclose(fp);
95 }