NOIP2005 等价表达式

题目：http://www.luogu.org/problem/show?pid=1054#
分析：用栈。。。恶心啊，140行到处是错，终于改对了。。
代码：

#include <cstdio>
#include <algorithm>
#include <cstring>
#include <stack>
#include <cmath>
using namespace std;
const long long int MOD=10007;
stack<long long int> Snum,Sopt;
int n;
long long int ans;
void clear(int num)
{
    int opt;
    long long int tmp1,tmp2;
    while(!Sopt.empty())
    {
        if(Sopt.top()<=num)
        {
            if(Sopt.top()==5){
                Sopt.pop();
                break;
            }
            opt=Sopt.top();
            Sopt.pop();
            tmp2=Snum.top();
            Snum.pop();
            tmp1=Snum.top();
            Snum.pop();
            if(opt==4) Snum.push((tmp1+tmp2)%MOD);
            else if(opt==3) Snum.push(tmp1-tmp2);
            else if(opt==2) Snum.push((tmp1*tmp2)%MOD);
            else
            {
                int i,Tmp=1;
                for(i=1;i<=tmp2;i++)
                  Tmp=(Tmp*tmp1)%MOD;
                Snum.push(Tmp);
            }
        }
        else break;
    }
    return;
}
int main()
{
    long long int num=0;
    char ch;
    while(scanf("%c",&ch)==1&&ch!='\n')
    {
        if(ch==' ') continue;
        if(ch=='(') Sopt.push(5);
        else if(ch==')'){
            if(num>0) Snum.push(num);
            clear(6);
            num=0;
        }
        else if(ch=='+'){
            if(num>0) Snum.push(num);
            clear(4);
            Sopt.push(4);
            num=0;
        }
        else if(ch=='-')
        {
            if(num>0) Snum.push(num);
            clear(3);
            Sopt.push(3);
            num=0;
        }
        else if(ch=='*'){
            if(num>0) Snum.push(num);
            clear(2);
            Sopt.push(2);
            num=0;
        }
        else if(ch=='^')
        {
            if(num>0) Snum.push(num);
            clear(1);
            Sopt.push(1);
            num=0;
        }
        else if(ch=='a') num=3;
        else num=(num*10+ch-'0')%MOD;
    }
    if(num>0) Snum.push(num);
    clear(10);
    ans=Snum.top();
    Snum.pop();
    scanf("%d",&n);
    getchar();
    for(int i=1;i<=n;i++)
    {
        num=0;
        while(scanf("%c",&ch)==1&&ch!='\n')
        {
            if(ch==' ') continue;
            if(ch=='(') Sopt.push(5);
            else if(ch==')'){
                if(num>0) Snum.push(num);
                clear(6);
                num=0;
            }
            else if(ch=='+'){
                if(num>0) Snum.push(num);
                clear(4);
                Sopt.push(4);
                num=0;
            }
            else if(ch=='-')
            {
                if(num>0) Snum.push(num);
                clear(3);
                Sopt.push(3);
                num=0;
            }
            else if(ch=='*'){
                if(num>0) Snum.push(num);
                clear(2);
                Sopt.push(2);
                num=0;
            }
            else if(ch=='^')
            {
                if(num>0) Snum.push(num);
                clear(1);
                Sopt.push(1);
                num=0;
            }
            else if(ch=='a') num=3;
            else num=(num*10+ch-'0')%MOD;
        }
        if(num>0) Snum.push(num);
        clear(10);
        int tmpans=Snum.top();
        if(ans==tmpans) printf("%c",'A'+i-1);
        Snum.pop();
    }
    return 0;
}