leetcode

0 class Solution {

1 public:

2 int calculate(string s) {

3 stringstream ss("+" + s);

4 char op;

5 int n, last, ans = 0;

6 while (ss >> op >> n) {

7 if (op == '+' || op == '-') {

8 n = op == '+' ? n : -n;

9 ans += n;

10 } else {

11 n = op == '*' ? last * n : last / n;

12 ans = ans - last + n;

13 }

14 last = n;

15 }

16 return ans;

17 }

18 };