CCF GESP 2024年6月认证 C++ 6级

#include <iostream>
using namespace std;
class my_class {
	public:
		static int count;
		my_class() {
			count++;
		}
		~my_class() {
			count--;
		}
		static void print_count() {
			cout << count << " ";
		}
};
int my_class::count = 0;
int main() {
	my_class obj1;
	my_class::print_count();
	my_class obj2;
	obj2.print_count();
	my_class obj3;
	obj3.print_count();
	return 0;
}

#include <iostream>
using namespace std;
 
class shape {
protected:
    int width, height;
public:
    shape(int a = 0, int b = 0) {
        width = a;
        height = b;
    }
    virtual int area() {
        cout << "parent class area: " << endl;
        return 0;
    }
};
 
class rectangle: public shape {
public:
    rectangle(int a = 0, int b = 0) : shape(a, b) { }
 
    int area() {
        cout << "rectangle area: ";
        return (width * height);
    }
};
 
class triangle: public shape {
public:
    triangle(int a = 0, int b = 0) : shape(a, b) { }
 
    int area() {
        cout << "triangle area: ";
        return (width * height / 2);
    }
};
 
int main() {
    shape *pshape;
    rectangle rec(10, 7);
    triangle tri(10, 5);
 
    pshape = &rec;
    pshape->area();
 
    pshape = &tri;
    pshape->area();
    return 0;
}

#include <iostream>
using namespace std;
 
stack<int> ten2bin(int n) {
    stack<int> st;
    int r, m;
 
    r = n % 2;
    m = n / 2;
    st.push(r);
 
    while (m != 1) {
        r = m % 2;
        st.push(r);
        m = m / 2;
    }
    st.push(m);
    return st;
}
 
int main() {
    int n;
    cin >> n;
    stack<int> bin;
    bin = ten2bin(n);
    while (!bin.empty()) {
        __________________ // 在此处填入代码
    }
    return 0;
}

#include <iostream>
 
using namespace std;
 
class circular_queue {
private:
    int *arr; // 数组用于存储队列元素
    int capacity; // 队列容量
    int front; // 队头指针
    int rear; // 队尾指针
 
public:
    circular_queue(int size) {
        capacity = size + 1; // 为了避免队列满时与队列空时指针相等的情况，多预留一个空间
        arr = new int[capacity];
        front = 0;
        rear = 0;
    }
 
    ~circular_queue() {
        delete[] arr;
    }
 
    bool is_empty() {
        return front == rear;
    }
 
    bool is_full() {
        _______________  // 在此处填入代码
    }
 
    void en_queue(int data) {
        if (is_full()) {
            cout << "队列已满，无法入队！" << endl;
            return -1;
        }
        arr[rear] = data;
        rear = (rear + 1) % capacity;
        return 1;
    }
 
    int de_queue() {
        if (is_empty()) {
            cout << "队列为空，无法出队！" << endl;
            return -1; // 出队失败，返回一个特殊值
        }
        int data = arr[front];
        front = (front + 1) % capacity;
        return data;
    }
};

int jump_recur(int n) {
    if (n == 1) return 1;
    if (n == 2) return 2;
    return jump_recur(n - 1) + jump_recur(n - 2);
}
 
int jump_dp(int n) {
    vector<int> dp(n + 1); // 创建一个动态规划数组，用于保存已计算的值
    // 初始化前两个数
    dp[1] = 1;
    dp[2] = 2;
    // 从第三个数开始计算斐波那契数列
    for (int i = 3; i <= n; ++i) {
        dp[i] = dp[i - 1] + dp[i - 2];
    }
    return dp[n];
}

#include <iostream>
#include <queue>
 
using namespace std;
 
// 二叉树节点的定义
struct TreeNode {
    int val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
};
 
// 宽度优先搜索（BFS）迭代实现
TreeNode* bfs(TreeNode* root, int a) {
    if (root == nullptr) return nullptr;
 
    queue<TreeNode*> q;
    q.push(root);
 
    while (!q.empty()) {
        TreeNode* node = q.front();
        q.pop();
 
        if (node->val == a)
            return node;
 
        cout << node->val << " "; // 先访问当前节点
 
        if (node->left) q.push(node->left); // 将左子节点入队
        if (node->right) q.push(node->right); // 将右子节点入队
    }
    return nullptr;
}

#include <iostream>
#include <stack>
 
using namespace std;
 
// 非递归深度优先搜索（DFS）
TreeNode* dfs(TreeNode* root, int a) {
    if (root == nullptr) return nullptr;
 
    stack<TreeNode*> stk;
    stk.push(root);
 
    while (!stk.empty()) {
        TreeNode* node = stk.top();
        stk.pop();
        if (node->val == a)
            return node;
 
        cout << node->val << " "; // 访问当前节点
 
        if (node->right) stk.push(node->right); // 先压入右子节点
        if (node->left) stk.push(node->left); // 再压入左子节点
    }
    return nullptr;
}