实验一 现代c++编程初体验

#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{0};
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);
 }

#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;
 }

#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';
 }

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

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 reversed_s = s;
    std::reverse(reversed_s.begin(), reversed_s.end());
    return s == reversed_s;
}

bool is_palindrome_ignore_case(const std::string &s) {
    std::string lower_s = s;
    std::transform(lower_s.begin(), lower_s.end(), lower_s.begin(),
                   [](unsigned char c) { return std::tolower(c); });
    std::string reversed_lower_s = lower_s;
    std::reverse(reversed_lower_s.begin(), reversed_lower_s.end());
    return lower_s == reversed_lower_s;
}

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

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) {
    if (x == 0) {
        return "0";
    }
    std::string result;
    int temp = x;
    while (temp > 0) {
        int remainder = temp % n;
        char c;
        if (remainder < 10) {
            c = '0' + remainder;
        } else {
            c = 'A' + remainder - 10;
        }
        result.push_back(c);
        temp /= n;
    }
    std::reverse(result.begin(), result.end());
    return result;
}

#include <iostream>
#include <string>
#include <iomanip>

int main() {
    for (char c = 'a'; c <= 'z'; ++c) {
        std::cout << c << " ";
    }
    std::cout << std::endl;
    for (int i = 1; i <= 26; ++i) {
        std::cout << std::setw(2) << i << " ";
        for (char c = 'A'; c <= 'Z'; ++c) {
            char cipher_char = 'A' + (c - 'A' + i) % 26;
            std::cout << cipher_char << " ";
        }
        std::cout << std::endl;
    }
    return 0;
}

#include <iostream>
#include <cstdlib>
#include <ctime>
#include <iomanip>

using namespace std;

int main() {
    srand(static_cast<unsigned int>(time(0)));
    int correctCount = 0;
    for (int i = 0; i < 10; ++i) {
        int num1 = rand() % 10 + 1; 
        int num2 = rand() % 10 + 1;
        char op;
        int result, userAnswer;

        int opType = rand() % 4;
        switch (opType) {
            case 0:
                op = '+';
                result = num1 + num2;
                break;
            case 1:
                op = '-';
                if (num1 < num2) {
                    swap(num1, num2);
                }
                result = num1 - num2;
                break;
            case 2:
                op = '*';
                result = num1 * num2;
                break;
            case 3:
                op = '/';
                while (num1 % num2 != 0) {
                    num1 = rand() % 10 + 1;
                    num2 = rand() % 10 + 1;
                }
                result = num1 / num2;
                break;
        }

        cout << num1 << " " << op << " " << num2 << " = ";
        cin >> userAnswer;

        if (userAnswer == result) {
            cout << "正确！" << endl;
            correctCount++;
        } else {
            cout << "错误，正确答案是：" << result << endl;
        }
    }

    double accuracy = static_cast<double>(correctCount) / 10 * 100;
    cout << "正确率：" << fixed << setprecision(2) << accuracy << "%" << endl;

    return 0;
}