实验1 现代c++编程初体验
任务1:
task1.cpp
1 // 现代C++标准库、算法库体验 2 // 本例用到以下内容: 3 // 1. 字符串string, 动态数组容器类vector、迭代器 4 // 2. 算法库：反转元素次序、旋转元素 5 // 3. 函数模板、const引用作为形参 6 7 #include <iostream> 8 #include <string> 9 #include <vector> 10 #include <algorithm> 11 12 using namespace std; 13 14 // 声明 15 // 模板函数声明 16 template<typename T> 17 void output(const T &c); 18 19 // 普通函数声明 20 void test1(); 21 void test2(); 22 void test3(); 23 24 int main() { 25 cout << "测试1: \n"; 26 test1(); 27 28 cout << "\n测试2: \n"; 29 test2(); 30 31 cout << "\n测试3: \n"; 32 test3(); 33 } 34 35 // 函数实现 36 // 输出容器对象c中的元素 37 template <typename T> 38 void output(const T &c) { 39 for(auto &i: c) 40 cout << i << " "; 41 cout << endl; 42 } 43 44 // 测试1 45 // 组合使用算法库、迭代器、string反转字符串 46 void test1() { 47 string s0{"0123456789"}; 48 cout << "s0 = " << s0 << endl; 49 50 string s1{s0}; 51 reverse(s1.begin(), s1.end()); // 反转指定迭代器区间的元素 52 cout << "s1 = " << s1 << endl; 53 54 string s2{s0}; 55 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 56 cout << "s2 = " << s2 << endl; 57 } 58 59 // 测试2 60 // 组合使用算法库、迭代器、vector反转动态数组对象vector内数据 61 void test2() { 62 vector<int> v0{2, 0, 4, 9}; 63 cout << "v0: "; 64 output(v0); 65 66 vector<int> v1{v0}; 67 reverse(v1.begin(), v1.end()); 68 cout << "v1: "; 69 output(v1); 70 71 vector<int> v2{v0}; 72 reverse_copy(v0.begin(), v0.end(), v2.begin()); 73 cout << "v2: "; 74 output(v2); 75 } 76 77 // 测试3 78 // 组合使用算法库、迭代器、vector实现元素旋转移位 79 void test3() { 80 vector<int> v0{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; 81 cout << "v0: "; 82 output(v0); 83 84 vector<int> v1{v0}; 85 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 86 cout << "v1: "; 87 output(v1); 88 89 vector<int> v2{v0}; 90 rotate(v2.begin(), v2.begin()+2, v2.end()); 91 cout << "v2: "; 92 output(v2); 93 94 vector<int> v3{v0}; 95 rotate(v3.begin(), v3.end()-1, v3.end()); 96 cout << "v3: "; 97 output(v3); 98 99 vector<int> v4{v0}; 100 rotate(v4.begin(), v4.end()-2, v4.end()); 101 cout << "v4: "; 102 output(v4); 103 }
运行测试截图
任务2：
task2.cpp
1 #include <iostream> 2 #include <vector> 3 #include <string> 4 #include <algorithm> 5 #include <numeric> 6 #include <iomanip> 7 8 using namespace std; 9 10 // 函数声明 11 // 模板函数声明 12 template<typename T> 13 void output(const T &c); 14 15 // 普通函数声明 16 int rand_int_100(); 17 void test1(); 18 void test2(); 19 20 int main() { 21 cout << "测试1: \n"; 22 test1(); 23 24 cout << "\n测试2: \n"; 25 test2(); 26 } 27 28 // 函数实现 29 // 输出容器对象c中的元素 30 template <typename T> 31 void output(const T &c) { 32 for(auto &i: c) 33 cout << i << " "; 34 cout << endl; 35 } 36 37 // 返回[0, 100]区间内的一个随机整数 38 int rand_int_100() { 39 return rand() % 101; 40 } 41 42 // 测试1 43 // 对容器类对象指定迭代器区间进行赋值、排序 44 void test1() { 45 vector<int> v0(10); // 创建一个动态数组对象v0, 对象大小为10 46 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 47 cout << "v0: "; 48 output(v0); 49 50 vector<int> v1{v0}; 51 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 52 cout << "v1: "; 53 output(v1); 54 55 vector<int> v2{v0}; 56 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 57 cout << "v2: "; 58 output(v2); 59 } 60 61 // 测试2 62 // 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 63 void test2() { 64 vector<int> v0(10); 65 generate(v0.begin(), v0.end(), rand_int_100); 66 cout << "v0: "; 67 output(v0); 68 69 auto iter1 = min_element(v0.begin(), v0.end()); 70 cout << "最小值: " << *iter1 << endl; 71 72 auto iter2 = max_element(v0.begin(), v0.end()); 73 cout << "最大值: " << *iter2 << endl; 74 75 auto ans = minmax_element(v0.begin(), v0.end()); 76 cout << "最小值: " << *(ans.first) << endl; 77 cout << "最大值: " << *(ans.second) << endl; 78 double avg1 = accumulate(v0.begin(), v0.end(), 0)/v0.size(); 79 cout << "均值: " << fixed << setprecision(2) << avg1 << endl; 80 81 cout << endl; 82 83 vector<int> v1{v0}; 84 cout << "v0: "; 85 output(v0); 86 sort(v1.begin(), v1.end()); 87 double avg2 = accumulate(v1.begin()+1, v1.end()-1, 0)/(v1.size()-2); 88 cout << "去掉最大值、最小值之后，均值: " << avg2 << endl; 89 }
运行测试截图
任务3：
task3.cpp
1 #include <iostream> 2 #include <string> 3 #include <algorithm> 4 5 bool is_palindrome(std::string s); 6 7 int main() { 8 using namespace std; 9 string s; 10 11 while(cin >> s) // 多组输入，直到按下Ctrl+Z后结束测试 12 cout << boolalpha << is_palindrome(s) << endl; 13 } 14 15 bool is_palindrome(std::string s){ 16 std::string m{s}; 17 reverse (m.begin(),m.end()); 18 return s==m; 19 }
运行测试截图
任务4：
task4.cpp
1 #include <iostream> 2 #include <string> 3 #include <algorithm> 4 5 std::string dec2n(int x, int n = 2); 6 7 int main() { 8 using namespace std; 9 10 int x; 11 while (cin >> x) { 12 cout << "十进制: " << x << endl; 13 cout << "二进制: " << dec2n(x) << endl; 14 cout << "八进制: " << dec2n(x, 8) << endl; 15 cout << "十六进制: " << dec2n(x, 16) << endl << endl; 16 } 17 } 18 19 std::string dec2n(int x, int n ) { 20 std::string s; 21 int a; 22 do { 23 a = x % n; 24 if (a < 10)s += a + '0'; 25 else s += 'A' + (a - 10); 26 x /= n; 27 } while (x != 0); 28 std::reverse(s.begin(), s.end()); 29 return s; 30 }
运行测试截图
任务5：
task5.cpp
1 #include<iostream> 2 #include<string> 3 #include<algorithm> 4 #include<iomanip> 5 #include<vector> 6 7 using namespace std; 8 9 template<typename T> 10 void output(const T& c); 11 12 int main() { 13 string s; 14 cout << " "; 15 for (int j = 0; j <= 25; j++) { 16 s = j + 'a'; 17 18 cout << setw(2) << s; 19 } 20 cout << endl; 21 vector<int>v0{ 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25 }; 22 for (int i = 0; i <= 25; i++) { 23 vector<int>vi{ v0 }; 24 int k=i+1; 25 rotate(vi.begin(), vi.begin() + k, vi.end()); 26 cout << setw(2) << i+1; 27 output(vi); 28 cout << endl; 29 } 30 31 } 32 template<typename T> 33 void output(const T& c) { 34 for (auto& i : c) { 35 string m; 36 m = i + 'A'; 37 cout << setw(2)<< m; 38 } 39 }
运行测试截图
任务6：
task6.cpp
1 #include<iostream> 2 #include<algorithm> 3 #include<iomanip> 4 #include<vector> 5 #include<string> 6 #include<cstdlib> 7 8 using namespace std; 9 10 int rand_int_10(int x = 11); 11 12 int rand_int(int y); 13 14 int main() { 15 int q = 0; 16 for (int i = 0; i < 10; i++) { 17 int x, y, z; 18 string m; 19 vector<string>s{ "+","-","*","/" }; 20 int random_index = rand() % s.size(); 21 if (random_index == 1) { 22 x = rand_int_10(); 23 y = rand_int_10(x); 24 } 25 else if (random_index == 3) { 26 x = rand_int_10(); 27 y = rand_int(x); 28 29 } 30 else { 31 x = rand_int_10(); 32 y = rand_int_10(); 33 } 34 m = s[random_index]; 35 cout << x << setw(2) << m << setw(2) << y << setw(2) << "="; 36 cin >> z; 37 switch (random_index) { 38 case 0: 39 if (z == x + y) q += 10; 40 break; 41 case 1: 42 if (z == x - y) q += 10; 43 break; 44 case 2: 45 if (z == x * y) q += 10; 46 break; 47 case 3: 48 if (z == x / y)q += 10; 49 break; 50 } 51 52 53 } 54 cout << "正确率:" << setprecision(2) << q << "%" << endl; 55 } 56 57 int rand_int_10(int x) { 58 return (rand() % (x - 1)) + 1; 59 } 60 61 int rand_int(int y) { 62 int m = y; 63 vector<int>e2{ 1,2 }; 64 vector<int>e3{ 1,3 }; 65 vector<int>e4{ 1,2,4 }; 66 vector<int>e5{ 1,5 }; 67 vector<int>e6{ 1,2,3,6 }; 68 vector<int>e7{ 1,7 }; 69 vector<int>e8{ 1,2,4,8 }; 70 vector<int>e9{ 1,3,9 }; 71 vector<int>e10{ 1,2,5,10 }; 72 switch (m) { 73 case 1:m = 1; 74 break; 75 case 2: 76 m = e2[rand() % e2.size()]; 77 78 break; 79 case 3: 80 m = e3[rand() % e3.size()]; 81 break; 82 case 4: 83 m = e4[rand() % e4.size()]; 84 break; 85 case 5: 86 m = e5[rand() % e5.size()]; 87 break; 88 case 6: 89 m = e6[rand() % e6.size()]; 90 break; 91 case 7: 92 m = e7[rand() % e7.size()]; 93 break; 94 case 8: 95 m = e8[rand() % e8.size()]; 96 break; 97 case 9: 98 m = e9[rand() % e9.size()]; 99 break; 100 case 10: 101 m = e10[rand() % e10.size()]; 102 break; 103 104 105 106 107 } 108 return m; 109 }
运行测试截图
