【Tyvj 1060】【NOIP 2005】等价表达式

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
typedef long long ll;
const int N = 10003;
const int a = 10007;
const int p = 100007;

char s[N], c[N], stf[N];
int num, now, stnum[N], topnum, sty[N], topfh;
int get(char c) {if (c == ‘+‘ || c == ‘-‘) return 1; if (c == ‘*‘) return 2; if (c == ‘^‘) return 3;}
bool fh(char c) {return c == ‘+‘ || c == ‘-‘ || c == ‘*‘ || c == ‘^‘ || c == ‘(‘ || c == ‘)‘;}
int ipow(int a, int b) {
	ll s = 1;
	for(int i = 1; i <= b; ++i)
		s = s * a % p;
	return (int) s;
}
int cal(char fh, int a, int b) {
	switch (fh) {
		case ‘+‘:
			return (a + b) % p;
		break;
		case ‘-‘:
			return (a - b + p) % p;
		break;
		case ‘*‘:
			return (int) (1ll * a * b % p);
		break;
		case ‘^‘:
			return ipow(a, b);
		break;
	}
}
int _() {
	int len = strlen(s), tmp = 0, j = 100, k;
	c[0] = ‘ ‘;
	for(int i = 0; i < len; ++i)
		if (s[i] != ‘ ‘) c[++tmp] = s[i];
	c[tmp + 1] = ‘ ‘;
	len = tmp; tmp = 1; topnum = topfh = 0;
	while (tmp <= len) {
		if (fh(c[tmp])) {
			if (c[tmp] == ‘(‘) j += 10;
			else if (c[tmp] == ‘)‘) j -= 10;
			else {
				k = get(c[tmp]);
				while (topfh && sty[topfh] >= k + j) {
					stnum[topnum - 1] = cal(stf[topfh], stnum[topnum - 1], stnum[topnum]);
					--topnum; --topfh;
				}
				stf[++topfh] = c[tmp]; sty[topfh] = k + j;
			}
			++tmp;
		} else {
			if (c[tmp] == ‘a‘) stnum[++topnum] = a, ++tmp;
			else {
				k = 0;
				for(;c[tmp] >= ‘0‘ && c[tmp] <= ‘9‘ && tmp <= len; ++tmp)
					k = k * 10 + c[tmp] - ‘0‘;
				stnum[++topnum] = k;
			}
		}
	}
	while (topfh) {
		stnum[topnum - 1] = cal(stf[topfh], stnum[topnum - 1], stnum[topnum]);
		--topnum; --topfh;
	}
	return stnum[1];
}
int main() {
	gets(s);
	num = _();
	int m;
	scanf("%d\n", &m);
	for(int i = 0; i < m; ++i) {
		gets(s);
		now = _();
		if (now == num) putchar(‘A‘ + i);
	}
	puts("");
	return 0;
}