coder计算器

花费了好长时间写了这段代码，准备提交呢，但是却发现无法粘贴到csdn的提交代码框中，所以也不知道正确与否，现在贴出来，希望大家批评指正！

#include<stdio.h>
#include<string.h>
double yunsuan(double a,double b,char op)
{
if(op=='+')
return a+b;
else if(op=='-')
return b-a;
else if(op=='*')
return a*b;
else if(op=='/')
return b/a;
else
{
int i;
double sum=1;
for(i=1;i<=a;i++)
sum=sum*b;
return sum;
}
}
int main()
{
int T,top,k,i,count=1,flag;
char ch[100],str[10],op;
double num[100],ovsa,ovsb,t,sum;
scanf("%d",&T);
while(T--)
{
top=-1;
k=-1;
while(scanf("%s",str)&&strcmp(str,"="))
{
if(str[0]=='(')
{
top++;
ch[top]=str[0];
}
else if(str[0]==')')
{
while(top>=0&&ch[top]!='(')
{
op=ch[top];
ovsa=num[k];
k--;
ovsb=num[k];
num[k]=yunsuan(ovsa,ovsb,op);
printf("%.3f%c%.3f=%.3f\n",ovsb,op,ovsa,num[k]);
top--;
}
top--;
}
else if(str[0]=='^')
{
top++;
ch[top]=str[0];
}
else if(str[0]=='*'||str[0]=='/')
{
while(ch[top]=='*'||ch[top]=='/'||ch[top]=='^')
{
op=ch[top];
ovsa=num[k];
k--;
ovsb=num[k];
num[k]=yunsuan(ovsa,ovsb,op);
printf("%.3f%c%.3f=%.3f\n",ovsb,op,ovsa,num[k]);
top--;
}
top++;
ch[top]=str[0];
}
else if(str[0]=='+'||str[0]=='-')
{
while(top>=0&&ch[top]!='(')
{
op=ch[top];
ovsa=num[k];
k--;
ovsb=num[k];
num[k]=yunsuan(ovsa,ovsb,op);
printf("%.3f%c%.3f=%.3f\n",ovsb,op,ovsa,num[k]);
top--;
}
top++;
ch[top]=str[0];
}
else
{
sum=0;
t=0.1;
for(i=0;str[i]!='\0';i++)
{
if(str[i]>='0'&&str[i]<='9')
{
sum=sum*10+(str[i]-'0');
}
else if(str[i]=='.')
{
i++;
while(str[i]!='\0')
{
sum+=(str[i]-'0')*t;
t=t*0.1;
i++;
}
}
}
k++;
num[k]=sum;
}
}
while(top>=0)
{
op=ch[top];
ovsa=num[k];
k--;
ovsb=num[k];
num[k]=yunsuan(ovsa,ovsb,op);
printf("%.3f%c%.3f=%.3f\n",ovsb,op,ovsa,num[k]);
top--;
}
printf("Case %d: %.3f\n",count++,num[k]);
}
return 0;
}