乱搞1

#include <cstdio>
#include <stack>
#include <cstring>
#define int long long
using namespace std;
const int MAXN = 30000;
char str[MAXN];
stack<int> numSTA;
stack<char> opSTA;

char ops[8] = {'+', '-', '*', '/', '(', ')', '^', '@'};
int matrix[8][8] = {
	{-1, -1, -1, -1,  1, -1,  -1,  1},
	{-1, -1, -1, -1,  1, -1,  -1,  1},
	{ 1,  1, -1, -1,  1, -1,  -1,  1},
	{ 1,  1, -1, -1,  1, -1,  -1,  1},
	{ 1,  1,  1,  1,  1,  1,   1,  1},
	{-1, -1, -1, -1,  0, -1,  -1,  1},
	{ 1,  1,  1,  1,  1, -1,  -1,  1},
	{-1, -1, -1, -1, -1, -1,  -1,  0}
};

int char_to_int(char ch) {
	for (int i = 0; i < 8; i++) {
		if (ops[i] == ch) return i;
	}
	return -1;
}

int calc(int a, char ch, int b) {
	if (ch == '+') return a + b;
	if (ch == '-') return a - b;
	if (ch == '*') return a * b;
	if (ch == '/') return a / b;
	if (ch == '^') {
		int ans = 1;
		while (b) {
			if (b & 1) {
				ans *= a;
			}
			a *= a;
			b >>= 1;
		}
		return ans;
	}
}

signed main() {
	scanf("%s", str + 1);
	int n = strlen(str + 1);
	str[++n] = '@';
	int num = 0;
	bool have_num = 0;
	opSTA.push('@');
	int ans = 0;
	for (int i = 1; i <= n;) {
		if (str[i] >= '0' && str[i] <= '9') {
			//nums
			have_num = 1;
			num = num * 10 + str[i] - '0';
		}
		else {
			//operator
			if (have_num) {
				numSTA.push(num);
				have_num = 0;
				num = 0;
			}
			char op = opSTA.top();
			int ret = matrix[char_to_int(str[i])][char_to_int(op)];
			if (ret == 1) {
				opSTA.push(str[i]);
			}
			else if (ret == -1) {
				opSTA.pop();
				int num2 = numSTA.top();
				numSTA.pop();
				int num1 = numSTA.top();
				numSTA.pop();
				numSTA.push(ans = calc(num1, op, num2));
//				printf("%d\n", ans);
				continue;
			}
			else if (ret == 0) {
				//break
				opSTA.pop();
			}
		}
		i++;
	}
	printf("%lld", ans);
	return 0;
}

支持

1. 加
2. 减
3. 乘
4. 除
5. 平方
6. 小括号