void check(char c, stack<char>& coll2, deque<char>& coll3)
{if (coll2.empty()){coll2.push(c);return;}if (isPra(c)){if (c == '(')coll2.push(c);else{while (coll2.top() != '('){char ch = coll2.top();coll3.push_back(ch);coll2.pop();}
            coll2.pop();}}else
    {char sym = coll2.top();        if (getPri(c) <= getPri(sym)){            coll2.pop();
            coll3.push_back(sym);
            check(c, coll2, coll3);}else{
            coll2.push(c);}}
}

void sz2(){int a, b, c, d, k1, k2, k3, count;char c1, c2, c3;double e, f;int k;count = 0;string str;for (int i = 0; i < 20; i++) {k1 = rand() % 4;if (k1 == 0)c1 = '+';else if (k1 == 1)c1 = '-';else if (k1 == 2)c1 = '*';else if (k1 == 3)c1 = '/';k2 = rand() % 4;if (k2 == 0)c2 = '+';else if (k2 == 1)c2 = '-';else if (k2 == 2)c2 = '*';else if (k2 == 3)c2 = '/';k3 = rand() % 4;if (k3 == 0)c3 = '+';else if (k3 == 1)c3 = '-';else if (k3 == 2)c3 = '*';else if (k3 == 3)c3 = '/';a = rand() % 10;b = rand() % 10;c = rand() % 10;d = rand() % 10;if (c1 == '/') {a = a*1.0;b = 2;}if (c2 == '/') {b = b*1.0;c = 2;}if (c3 == '/') {c = c*1.0;d = 2;}stringstream ss1;stringstream ss2;stringstream ss3;string s1;string s2;string s3;ss1 << "(" << a << c1 << b << ")" << c2 << c << c3 << d;ss2 << a << c1 << "(" << b << c2 << c << ")" << c3 << d;ss3 << a << c1 << b << c2 << "(" << c << c3 << d << ")";s1 = ss1.str();s2 = ss1.str();s3 = ss1.str();k = rand() % 3;if (k == 0)str = s1;else if (k1 == 1)str = s2;else if (k1 == 2)str = s3;cout << str << "=" << endl;deque<char> coll1;          stack<char> coll2; deque<char> coll3;   stack<int>coll4;  for (int i = 0; i != str.size(); ++i){            coll1.push_back(str[i]);}        allocate(coll1, coll2, coll3);        calculate(coll3, coll4);f = coll4.top();cout << "?";cin >> e;if (e == f) {cout << "答对啦，你真是个天才!" << endl;count++;}else if (e != f) {cout << "再想想吧，答案似乎是" << f << "喔!" << endl;}    }cout << "...(一共20道题)" << endl;cout << endl;cout << "你一共答对" << count << "道题，共20道题。" << endl;
}

void main(int argc, char *argv[])
{if (argc == 1) {sz2();}else {int b1;float b2 = atof(argv[2]);if ((b2 - (int)b2) > 0){cout << "题目数量必须是 正整数。";exit(0);}else {b1 = atoi(argv[2]);if (!(*argv[2] == '+' || (*argv[2] > '0'&& *argv[2] <= '9') || *argv[2] == '.')) {cout << "题目数量必须是 正整数。";exit(0);}sz3(b1);}}}

ofstream fout;
fout.open("f4.txt");
fout << str << "=" << "\t" << "\t" << std::left << f << endl;
fout.close();

要求2 给出照片1张，包括结对的2位同学、工作地点、计算机，可选项包括其他能表达结对编程工作经历的物品或场景

结对成员：王伟东、李圆圆

工作地点：计算机楼107教室

计算机：联想电脑，操作系统为64位，内存为8g

编程经历：应老师的要求，结对编程需在物理空间下，相距一两米的距离，所以在选用了在无人上课的教室进行实际操作，因为工作地点的不稳定因素，所以要随时更换工作地点，打断工作进程，效率降低，其次因为事先工作习惯的原因，在电源突然切断的情况下，对所完成的代码进行提前保存，避免大量工作的重复进行。

照片：

要求3 使用coding.net做版本控制。checkin 前要求清理 临时文件、可执行程序，通常执行 build-clean可以达到效果