leetcode

0 class Solution {

1 public:

2 int calculate(const string &s) const {

3 int res = 0;

4 vector<int> signs(2, 1);

5 for (int i = 0; i < s.size(); i++) {

6 if (s[i] >= '0') {

7 int number = 0;

8 while (i < s.size() && isdigit(s[i])) {

9 number = 10 * number + (s[i++] - '0');

10 }

11 res += signs.back() * number;

12 signs.pop_back();

13 i--;

14 } else if (s[i] == '(' && s[i + 1] == '-') {

15 } else if (s[i] == ')')

16 signs.pop_back();

17 else if (s[i] != ' ')

18 signs.push_back(signs.back() * (s[i] == '-' ? -1 : 1));

19 }

20 return res;

21 }

22 };