2017.netease.expression.cpp

#include <iostream>
#include <string>
#include <cstdio>
#include <cstring>
#include <vector>
#include <queue>
#include <cmath>
#include <map>
#include <unordered_map>
#include <unordered_set>
using namespace std;

#define ff(i, n) for (int i = 0, END = (n); i < END; i ++)
#define fff(i, n, m) for (int i = (n), END = (m); i <= END; i ++)
#define dff(i, n, m) for (int i = (n), END = (m); i >= END; i --)
#define travel(e, first) for (int e = first, v = vv[first]; ~e; e = nxt[e], v = vv[e])
#define clr(a, b) memset(a, b, sizeof(a))
typedef long long ll;

int main() {
    string in;
    while (cin >> in) {
        ll now = 0;
        char op = '+';

        for (char ch: in) {
            if (isdigit(ch)) {
                int num = ch - '0';
                if (op == '+') { now += num; }
                if (op == '-') { now -= num; }
                if (op == '*') { now *= num; }
            } else {
                op = ch;
            }
        }

        cout << now << endl;
    }
}