hdu 4140 模拟

#include <stdio.h>
#include <string.h>
#define N 1000000

char str[N];
int x;
int pow(int a,int b)
{
    int res =  1;
    while(b--)
        res *= a;
    return res;
}
int solve()
{
    int res = 0,add = 0,flag = 1,c,e;
    int i = 0,j = 0;
    int len = strlen(str);
    for(--len; str[len]!='+' && str[len] != '-' && len >= 0; --len);
    if(str[0] == '-')
    {
        flag = -1;
        i = 1;
    }
    for(;i < len; ++i)
    {
        c = 0;
        for(j = i; str[j] != 'X'; ++j)
            c = c*10 + str[j] - '0';
        if(i == j)
            c = 1;
        ++j;
        if(str[j] == '^')
        {
            e = 0;
            for(++j;str[j] != '+' && str[j] !='-';++j)
                e = e * 10 + str[j] -