python/LuoGu/RuMen/P2788.cpp

#include <bits/stdc++.h>

using namespace std;

char a[1010101];//KAO,第一次下手不够狠，居然RE了两个点！！
queue<string> q1;
queue<char> q2;

int main() {
    scanf("%s", a);
    string s1 = "", s2 = "";

    for (int i = 0; a[i] != '\0';) {
        //数字
        while (a[i] >= '0' && a[i] <= '9') {
            s1 += a[i];
            i++;
        }
        if (s1.size() > 0) {
            q1.push(s1);
            s1.clear();
        }
        //操作符
        if (a[i] == '+' || a[i] == '-') {
            q2.push(a[i]);
            i++;
        }
    }
    long result;
    //字符串转数字长整型
    istringstream(q1.front()) >> result;
    q1.pop();

    while (!q1.empty()) {
        long second;
        istringstream(q1.front()) >> second;
        q1.pop();
        char c = q2.front();
        q2.pop();

        if (c == '+') {
            result += second;
        } else {
            result -= second;
        }
    }
    cout << result << endl;
    return 0;
}