实验一

实验任务1

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
template<typename T>
void output(const T &c);
void test1();
void test2();
void test3();
int main()
{
    std::cout << "测试1: \n";
    test1();
    std::cout << "\n测试2: \n";
    test2();
    std::cout << "\n测试3: \n";
    test3();
}
template <typename T>
void output(const T &c)
{
    for(auto &i : c)
        std::cout << i << ' ';
    std::cout << '\n';
}
void test1()
{
    using namespace std;
    string s0{"0123456789"};
    cout << "s0 = " << s0 << endl;
    string s1(s0);
    reverse(s1.begin(), s1.end());  
    cout << "s1 = " << s1 << endl;
    string s2(s0.size(), ' ');
    reverse_copy(s0.begin(), s0.end(), s2.begin()); 
    cout << "s2 = " << s2 << endl;
}
void test2()
{
    using namespace std;
    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);
}
void test3()
{
    using namespace std;
    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());  
    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:

任务一结果截图

问题1:

reverse直接将字符串反转,reverse_copy将反转后的字符串复制到新的字符串,但不改变原字符串

问题2:

rotate将从begin为起点到begin+n之前的元素移动到end后面,第一、二个参数代表要移动的元素的范围,第三个参数代表移动到的位置

实验任务2

#include <iostream>
#include <vector>
#include <algorithm>
#include <numeric>
#include <iomanip>
#include <cstdlib>
#include <ctime>
template<typename T>
void output(const T &c);
int generate_random_number();
void test1();
void test2();
int main()
{
    std::srand(std::time(0));
    std::cout << "测试1: \n";
    test1();
    std::cout << "\n测试2: \n";
    test2();
}
template <typename T>
void output(const T &c)
{
    for(auto &i: c)
        std::cout << i << ' ';
    std::cout << '\n';
}
int generate_random_number()
{
    return std::rand() % 101;
}
void test1()
{
    using namespace std;
    vector<int> v0(10);
    generate(v0.begin(), v0.end(), generate_random_number);
    cout << "v0: "; output(v0);
    vector<int> v1{v0};
    sort(v1.begin(), v1.end());
    cout << "v1: "; output(v1);
    vector<int> v2{v0};
    sort(v2.begin()+1, v2.end()-1);
    cout << "v2: "; output(v2);
}
void test2()
{
    using namespace std;
    vector<int> v0(10);  
    generate(v0.begin(), v0.end(), generate_random_number); 
    cout << "v0: "; output(v0);
    auto min_iter = min_element(v0.begin(), v0.end());
    auto max_iter = max_element(v0.begin(), v0.end());
    cout << "最小值: " << *min_iter << endl;
    cout << "最大值: " << *max_iter << 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(), 0.0) / v0.size();
    cout << "均值: " << fixed << setprecision(2) << avg1 << endl;
    sort(v0.begin(), v0.end());
    double avg2 = accumulate(v0.begin()+1, v0.end()-1, 0.0) / (v0.size()-2);
    cout << "去掉最大值、最小值之后,均值: " << avg2 << endl;
}

运行结果:

任务二结果截图

问题1:

generate作用是给v0赋值

问题2:

minmax_element是代码效率更高,更简洁

问题3:

效果相同,lambda可以在需要函数的地方直接定义和使用

实验任务3

#include <iostream>
#include <string>
#include <algorithm>
#include <cctype>
unsigned char func(unsigned char c);
void test1();
void test2();
int main()
{
    std::cout << "测试1: 字符串大小写转换\n";
    test1();

    std::cout << "\n测试2: 字符变换\n";
    test2();
}
unsigned char func(unsigned char c)
{
    if(c == 'z')
        return 'a';
    if(c == 'Z')
        return 'A';
    if(std::isalpha(c))
        return static_cast<unsigned char>(c+1);
    return c;
}
void test1()
{
    std::string s1{"Hello World 2049!"};
    std::cout << "s1 = " << s1 << '\n';
    std::string s2;
    for(auto c: s1)
        s2 += std::tolower(c);
    std::cout << "s2 = " << s2 << '\n'; 
    std::string s3;
    for(auto c: s1)
        s3 += std::toupper(c);
    std::cout << "s3 = " << s3 << '\n'; 
}
void test2()
{
    std::string s1{"I love cosmos!"};
    std::cout << "s1 = " << s1 << '\n';
    std::string s2(s1.size(), ' ');
    std::transform(s1.begin(), s1.end(),
                   s2.begin(),
                   func);
    std::cout << "s2 = " << s2 << '\n';
}

运行结果:

任务三截图

问题1:

func函数的功能是将字母后移一位

问题2:

tolower的功能是将字母转换成小写,toupper的功能是将字母转换成大写

问题3:

transform的第一、二个参数是选择的范围,第三个参数是所选元素处理后移动到的位置,第四个参数是函数,对所选元素进行处理,第三个参数没改之前,s1不变,改为s1.begin()后,s1会被改为处理后的结果

实验任务4

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

bool is_palindrome(const std::string &s);
bool is_palindrome_ignore_case(const std::string &s);

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

    while(cin >> s) {
        cout << boolalpha 
             << "区分大小写: " << is_palindrome(s) << "\n"
             << "不区分大小写: " << is_palindrome_ignore_case(s) << "\n\n";
    }     
}

bool is_palindrome(const std::string &s)
{
    std::string s0{s};
    reverse(s0.begin(),s0.end());
    if(s0 == s)
        return true;
    return false;
}

bool is_palindrome_ignore_case(const std::string &s)
{
    std::string s1;
    for(auto i:s)
        s1 += std::tolower(i);
    std::string s2{s1};
    reverse(s1.begin(),s1.end());
    if(s1 == s2)
        return true;
    return false;
}

运行结果:

任务四截图

问题1:

使用std::getline函数

实验任务5

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

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

int main() {
    int x;
    while(std::cin >> x) {
        std::cout << "十进制: " << x << '\n'
                  << "二进制: " << dec2n(x) << '\n'
                  << "八进制: " << dec2n(x, 8) << '\n'
                  << "十二进制: " << dec2n(x, 12) << '\n'
                  << "十六进制: " << dec2n(x, 16) << '\n'
                  << "三十二进制: " << dec2n(x, 32) << "\n\n"; 
    }
}

std::string dec2n(int x, int n)
{
    std::string s;
    do
    {
        char c;
        int t = x % n;
        if(t < 10)
            c = '0' + t;
        else
            c = 'A' + t - 10;
        s.push_back(c);
        x /= n;
    }while(x > 0);
    reverse(s.begin(),s.end());
    return s;
}

运行结果:

任务五截图

实验任务6

#include <iostream>
#include <iomanip>
#include <string>
#include <cctype>
#include <algorithm>
using namespace std;
int main()
{
    char s1[26];
    for(int i = 0;i < 26;i++)
        s1[i] = 'a' + i;
    cout << "  ";
    for(int i = 0;i < 26;i++)
        cout << " " << s1[i];
    cout << "\n";
    string s2;
    for(auto i:s1)
        s2 += toupper(i);
    for(int i = 1;i <= 26;i++)
    {
        cout << setw(2) << i;
        rotate(s2.begin(),s2.begin()+1,s2.end());
        for(int j = 0;j < 26;j++)
            cout << " " << s2[j];
        cout << "\n";
    }
    
}

运行结果:

任务六截图

实验任务7

#include <iostream>
#include <cstdlib>
#include <ctime>
#include <iomanip>
using namespace std;
int main()
{
    srand(time(0));
    int t = 0;
    double s;
    for(int i = 0;i < 10;i++)
    {
        int a = rand()%10 + 1;
        int b = rand()%10 + 1;
        int x = rand()%4;
        int s1,s2;
        char c;
        switch(x)
        {
            case 0:
                c = '+';
                s1 = a + b;
                break;
            case 1:
                while(a < b)
                {
                    a = rand()%10 + 1;
                    b = rand()%10 + 1;
                }
                c = '-';
                s1 = a - b;
                break;
            case 2:
                c = '*';
                s1 = a * b;
                break;
            case 3:
                c = '/';
                while(a < b||a % b!=0)
                {
                    a = rand()%10 + 1;
                    b = rand()%10 + 1;
                }
                s1 = a / b;
                break;
        }
        cout << a << ' ' << c << ' ' << b << " = ";
        cin >> s2;
        if(s1 == s2)
            t++;
    }
    s = t * 10;
    cout << "正确率:" << fixed << setprecision(2) << s << '%'; 
}

运行结果:

任务七1

任务七2

 

posted @ 2025-10-15 21:51  系统警告  阅读(5)  评论(0)    收藏  举报