Stress test

//#include<stdio.h>

#include <bits/stdc++.h>

using namespace std;

inline int f(int a, int b) {
    // любая функция
    return a + b;
}

int n;
vector<int> tree(2 * 10000 + 1);

inline int get(int left, int right) {
    left += n;
    right += n;
    int ans = -1;
    while (left <= right) {
        // 0101 = 1 + 4 = 5
        // 0001
        if ((left & 1) != 0) { // если отрезок из ДО входит в наш запрос - добавим его
            if (ans == -1) {
                ans = tree[left];
            } else {
                ans = f(ans, tree[left]);
            }
            ++left;
        }
        if ((right & 1) == 0) { // если отрезок из ДО входит в наш запрос - добавим его
            if (ans == -1) {
                ans = tree[right];
            } else {
                ans = f(ans, tree[right]);
            }
            --right;
        }
        left >>= 1;
        right >>= 1;
    }
    return ans;
}

//void setValue(int i, int value, vector<int>& tree) {
//    i += n; // добавляется размер массива
//    tree[i] = value;
//    i >>= 1;
//    while(i > 0) {
//        tree[i] = f(tree[i << 1], tree[(i << 1) + 1]);
//        i >>= 1;
//    }
//}

std::mt19937 ran(time(0));

int irand(int a, int b) {
    return a + ran() % (b - a + 1);
}

struct Request {
    char type;
    int a, b;
    void print() {
        cout << type << " " << a << " " << b << "\n";
    }
};

struct Test {
    int n, m;
    vector<int> elements;
    vector<Request> q;

    Test(int _n, int _m, vector<Request> &_q) {
        n = _n;
        m = _m;
        q = _q;
    }

    Test() {}

    void print() {
        cout << n << " " << m << "\n";
        for (int i : elements) {
            cout << i << " ";
        }
        cout << "\n";
        for (auto &i : q) {
            i.print();
        }
    }
};

Test gen() {
    Test test;
    test.n = irand(3, 10);
    test.m = irand(3, 10);
    test.elements.resize(test.n);
    test.q.resize(test.m);
    for (int &i : test.elements) {
//        cout << "fdfd";
        i = irand(2, 10);
    }
    for (int i = 0; i < test.m; ++i) {
//        cout << "opop";
        Request req;
        test.q[i].type = 'Q';
//        req.type = 'Q';
//        if (test.q[i].type == 'A') {
//            test.q[i].a = irand(1, test.n);
//            test.q[i].b = irand(1, 10);
//        } else {
            test.q[i].a = irand(1, test.n / 2);
            test.q[i].b = irand(req.a, test.n);
//        }
    }
    return test;
}

struct Answer {
    int _size;
    vector<int> answers;
};

bool checker(Answer &right, Answer &wrong, Test &test) {
    if (wrong._size != right._size) {
        cout << "wrong answer\n";
        cout << "right size:" << right._size << " wrong size:" << wrong._size;
        test.print();
        return false;
    }
    int _size = right._size;
    vector<string> ans(_size);
    bool mistake = false;
    for (int i = 0; i < _size; ++i) {
//        cout << "tt";
        if (right.answers[i] != wrong.answers[i]) {
            mistake = true;
            ans[i] = "WA";
        } else {
            ans[i] = "OK";
        }
    }
    if (mistake) {
        test.print();
        for (int i = 0; i < ans.size(); ++i) {
//            cout << "yt";
            if (ans[i] == "OK") {
                cout << "OK: " << right.answers[i] << "\n";
            } else {
                cout << "WA: " << "r: " << right.answers[i] << " w: " << wrong.answers[i] << "\n";
            }
        }
        return false;
    }
    return true;
}

Answer genRightAnswer(const Test &test) {
    Answer ans;
    ans.answers = {};
    ans._size = 0;
    vector<int> v = test.elements;
    for (auto q : test.q) {
        cout << 'f';
//        cin >> q.type >> q.a >> q.b;
        if (q.type == 'Q') {
            int sum = 0;
            for (int j = q.a - 1; j <= q.b - 1; ++j) {
//                cout << q.a << " " << q.b << "\n";
//                cout << 'y';
                sum += v[j];
            }
            ans.answers.push_back(sum);
            ans._size++;
        }
//            v[q.a - 1] = q.b;
//        } else {
//            v[q.a - 1] = q.b;

//        }
    }
    cout << ans._size << "try\n ";
    return ans;
}

Answer genTryAnswer(const Test &test) {
    Answer ans;
    ans.answers = {};
    ans._size = 0;
    n = test.n;
    for (int i = test.n; i < 2 * test.n; ++i)  {
        tree[i] = test.elements[i - test.n]; // считываем массив
    }
    for (int i = test.n - 1; i >= 1; --i)
        tree[i] = f(tree[i << 1], tree[(i << 1) + 1]); // построение дерева отрезков \/\/\/\/\/\/\/
    for (auto q : test.q) {
        if (q.type == 'Q') {
            ans.answers.push_back(get(q.a - 1, q.b - 1));
        }
    }
    cout << ans._size << "try\n ";
    tree.assign(2 * 10000 + 1, 0);
    return ans;
}

int main() {
    int count;
    cout << "count tests: ";
    cin >> count;
    while (count--) {
        Test test = gen();
        Answer right = genRightAnswer(test);
        Answer wrong = genTryAnswer(test);
        if (!checker(right, wrong, test)) {
            return 0;
        }
    }
    cout << "OK!";
}