实验1

任务1：

task1.cpp

// 现代C++标准库、算法库体验
// 本例用到以下内容:
// 1. 字符串string, 动态数组容器类vector、迭代器
// 2. 算法库：反转元素次序、旋转元素
// 3. 函数模板、const引用作为形参

#include <iostream> 
#include <string> 
#include <vector> 
#include <algorithm>

using namespace std; 

// 声明 
// 模板函数声明 
template<typename T> 
void output(const T &c);

// 普通函数声明 
void test1(); 
void test2(); 
void test3();

int main() { 
    cout << "测试1: \n"; 
    test1(); 
    
    cout << "\n测试2: \n"; 
    test2(); 
    
    cout << "\n测试3: \n"; 
    test3();
}

// 函数实现 
// 输出容器对象c中的元素 
template <typename T> 
void output(const T &c) { 
    for(auto &i: c) 
        cout << i << " "; 
    cout << endl; 
}

// 测试1 
// 组合使用算法库、迭代器、string反转字符串 
void test1() { 
    string s0{"0123456789"}; 
    cout << "s0 = " << s0 << endl; 
    
    string s1{s0}; 
    reverse(s1.begin(), s1.end()); // 反转指定迭代器区间的元素 
    cout << "s1 = " << s1 << endl;
    
    string s2{s0}; 
    reverse_copy(s0.begin(), s0.end(), s2.begin()); // 将指定迭代区间的元素拷贝 到指定迭代器开始的目标区间，并且在复制过程中反转次序 
    cout << "s2 = " << s2 << endl; 
}

// 测试2 
// 组合使用算法库、迭代器、vector反转动态数组对象vector内数据 
void test2() { 
    vector<int> v0{2, 0, 4, 9}; 
    cout << "v0: "; 
    output(v0);
    
    vector<int> v1{v0}; 
    reverse(v1.begin(), v1.end()); 
    cout << "v1: "; 
    output(v1); 
    
    vector<int> v2{v0}; 
    reverse_copy(v0.begin(), v0.end(), v2.begin()); 
    cout << "v2: "; 
    output(v2); 
}

// 测试3 
// 组合使用算法库、迭代器、vector实现元素旋转移位 
void test3() { 
    vector<int> v0{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; 
    cout << "v0: "; 
    output(v0); 
    
    vector<int> v1{v0}; rotate(v1.begin(), v1.begin()+1, v1.end()); // 旋转指定迭代器区间 [v1.begin(), v1.end())之间的数据项，旋转后从迭代器v1.begin()+1位置的数据项开始 
    cout << "v1: ";
    output(v1); 
    
    vector<int> v2{v0}; 
    rotate(v2.begin(), v2.begin()+2, v2.end()); 
    cout << "v2: "; 
    output(v2); 
    
    vector<int> v3{v0}; 
    rotate(v3.begin(), v3.end()-1, v3.end()); 
    cout << "v3: "; 
    output(v3); 
    
    vector<int> v4{v0}; 
    rotate(v4.begin(), v4.end()-2, v4.end()); 
    cout << "v4: "; 
    output(v4); 
}

运行结果截图：

 

任务2：

task2.cpp

#include <iostream> 
#include <vector> 
#include <string> 
#include <algorithm> 
#include <numeric> 
#include <iomanip> 

using namespace std;

// 函数声明 
// 模板函数声明 
template<typename T> 
void output(const T &c);

// 普通函数声明 
int rand_int_100(); 
void test1(); 
void test2(); 

int main() { 
    cout << "测试1: \n"; 
    test1(); 
    
    cout << "\n测试2: \n"; 
    test2(); 
}

// 函数实现 
// 输出容器对象c中的元素
template <typename T> 
void output(const T &c) { 
    for(auto &i: c) 
        cout << i << " "; 
    cout << endl; 
}

// 返回[0, 100]区间内的一个随机整数 
int rand_int_100() { 
    return rand() % 101; 
}

// 测试1 
// 对容器类对象指定迭代器区间进行赋值、排序 
void test1() { 
    vector<int> v0(10); // 创建一个动态数组对象v0, 对象大小为10 
    generate(v0.begin(), v0.end(), rand_int_100); // 产生[0, 100]之间的随机整数 赋值给指定迭代器区间[v0.begin(), v0.end())内的每个数据项 
    cout << "v0: "; 
    output(v0);
    
    vector<int> v1{v0}; 
    sort(v1.begin(), v1.end()); // 对指定迭代器区间[v1.begin(), v1.end())内数据 项进行升序排序 
    cout << "v1: "; 
    output(v1);
    
    vector<int> v2{v0}; 
    sort(v2.begin()+1, v2.end()-1); // 对指定迭代器区间[v1.begin()+1, v1.end()-1)内数据项进行升序排序 
    cout << "v2: "; 
    output(v2); 
}

// 测试2 
// 对容器类对象指定迭代器区间进行赋值、计算最大值/最小值/均值 
void test2() { 
    vector<int> v0(10); 
    generate(v0.begin(), v0.end(), rand_int_100); 
    cout << "v0: "; 
    output(v0);
    
    auto iter1 = min_element(v0.begin(), v0.end()); 
    cout << "最小值: " << *iter1 << endl; 
    
    auto iter2 = max_element(v0.begin(), v0.end()); 
    cout << "最大值: " << *iter2 << endl; 
    
    auto ans = minmax_element(v0.begin(), v0.end()); 
    cout << "最小值: " << *(ans.first) << endl; 
    cout << "最大值: " << *(ans.second) << endl; 
    double avg1 = accumulate(v0.begin(), v0.end(), 0)/v0.size(); 
    cout << "均值: " << fixed << setprecision(2) << avg1 << endl; 
    
    cout << endl;
    
    vector<int> v1{v0}; 
    cout << "v0: "; 
    output(v0); 
    sort(v1.begin(), v1.end()); 
    double avg2 = accumulate(v1.begin()+1, v1.end()-1, 0)/(v1.size()-2); 
    cout << "去掉最大值、最小值之后，均值: " << avg2 << endl; 
}

运行结果截图：

 

任务3：
task3.cpp

#include <iostream>
#include <string>
#include <algorithm>

bool is_palindrome(std::string s);

int main() {
    using namespace std;
    string s;

    while(cin >> s)  // 多组输入，直到按下Ctrl+Z后结束测试
        cout << boolalpha << is_palindrome(s) << endl;
}

// 函数is_palindrom定义
bool is_palindrome(std::string s){
    using namespace std;
    bool a=false,b=true;
    string str = s;
    int len = s.size();
    char temp;
    for(int i=0; i<len/2; i++){
        temp = s[i];
        s[i]=s[len-i-1];
        s[len-i-1]=temp;
    }
    if(str==s)
        return true;
    else
        return false;
}

运行结果截图

 

任务4

task4.cpp

#include <iostream>
#include <string>
#include <algorithm>

std::string dec2n(int x, int n = 2);

int main() {
    using namespace std;

    int x;
    while(cin >> x) {
        cout << "十进制: " << x << endl;
        cout << "二进制: " << dec2n(x) << endl;
        cout << "八进制: " << dec2n(x, 8) << endl;
        cout << "十六进制: " << dec2n(x, 16) << endl << endl;
    }
}

// 函数dec2n定义
std::string dec2n(int x, int n) {
    if (x == 0) 
        return "0";  
    const char digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";  
    std::string result;  
    while (x > 0) {  
        result += digits[x % n];  
        x /= n;  
    }  
    std::reverse(result.begin(), result.end());  
    return result;  
} 

运行结果截图

 

任务5：
task5.cpp

 

#include<iostream> 
#include<iomanip>
using namespace std;
int main()
{
    int count=1; 
    int i,j;
    cout<<"  ";
    for(i=97;i<97+26;i++) 
    {
        cout<<setw(2)<<char(i);
    }
    cout<<endl;
    for(i=1;i<=26;i++)
    {
        cout<<setw(2)<<i;
        for(j=i+1;j<=26;j++)
        {
            cout<<setw(2)<<char(j+64);
        }
        for(j=1;j<=i;j++)
        {
            cout<<setw(2)<<char(j+64);
        }
        cout<<endl;
    }
    return 0;
}

 

运行结果截图

 

 

 

任务6：

task6.cpp

 

#include <iostream>  
#include <cstdlib>  
#include <ctime>  
#include <iomanip>  
  
using namespace std;  
  
int randomInRange(int min, int max) {  
    return rand() % (max - min + 1) + min;  
}  
  
pair<int, int> generateDivisiblePair() {  
    int divisor = randomInRange(1, 10);  
    int dividend = divisor * randomInRange(1, 10);
    return {dividend, divisor};  
}  
  
pair<int, int> generateSubtractPair() {  
    int minuend = randomInRange(2, 10); 
    int subtrahend = randomInRange(1, minuend - 1);
    return {minuend, subtrahend};  
}  
  
double generateAndEvaluateQuestions() {  
    srand(static_cast<unsigned>(time(0)));
    int correctAnswers = 0;  
      
    for (int i = 0; i < 10; ++i) {  
        int operation = randomInRange(0, 3);
        pair<int, int> operands;  
          
        switch (operation) {  
            case 0:
                operands = {randomInRange(1, 10), randomInRange(1, 10)};  
                cout << operands.first << " + " << operands.second << " = ";  
                break;  
            case 1:
                operands = generateSubtractPair();  
                cout << operands.first << " - " << operands.second << " = ";  
                break;  
            case 2:
                operands = {randomInRange(1, 10), randomInRange(1, 10)};  
                cout << operands.first << " * " << operands.second << " = ";  
                break;  
            case 3:
                operands = generateDivisiblePair();  
                cout << operands.first << " / " << operands.second << " = ";  
                break;  
        }  
          
        int userAnswer;  
        cin >> userAnswer;  
          
        int correctAnswer;  
        switch (operation) {  
            case 0: correctAnswer = operands.first + operands.second; break;  
            case 1: correctAnswer = operands.first - operands.second; break;  
            case 2: correctAnswer = operands.first * operands.second; break;  
            case 3: correctAnswer = operands.first / operands.second; break;  
        }  
          
        if (userAnswer == correctAnswer) {  
            ++correctAnswers;  
        }  
    }  
      
    double accuracy = static_cast<double>(correctAnswers) / 10 * 100;  
    cout << fixed << setprecision(2) << "正确率: " << accuracy << "%" << endl;  
      
    return accuracy;  
}  
  
int main() {  
    generateAndEvaluateQuestions();  
    return 0;  
}

 

运行结果截图