实验1 现代C++编程初体验
任务一
源代码
1 #include<iostream> 2 #include<string> 3 #include<vector> 4 #include<algorithm> 5 6 using namespace std; 7 8 template<typename T> 9 void output(const T& c); 10 11 void test1(); 12 void test2(); 13 void test3(); 14 15 int main() { 16 cout << "测试1: \n"; 17 test1(); 18 19 cout << "\n测试2: \n"; 20 test2(); 21 22 cout << "\n测试3: \n"; 23 test3(); 24 } 25 26 27 //输出c中的元素，c容器对象 28 template<typename T> 29 void output(const T& c) { 30 for (auto& i : c) 31 cout << i << " "; 32 cout << endl; 33 } 34 35 36 37 //组合使用算法库，迭代器，string反转字符串 38 void test1() { 39 string s0{ "0123456789" }; 40 cout << "s0=" << s0 << endl; 41 42 string s1{ s0 }; 43 reverse(s1.begin(), s1.end()); 44 cout << "s1 = " << s1 << endl; 45 46 string s2{ s0 }; 47 reverse_copy(s0.begin(), s0.end(), s2.begin()); 48 cout << "s2 = " << s2 << endl; 49 } 50 51 52 53 //vector反转动态数组 54 void test2() { 55 vector<int>v0{ 2,0,4,9 }; 56 cout << "v0: "; 57 output(v0); 58 59 vector<int>v1{ v0 }; 60 reverse(v1.begin(), v1.end()); 61 cout << "v1:"; 62 output(v1); 63 64 vector<int>v2{ v0 }; 65 reverse_copy(v0.begin(), v0.end(), v2.begin()); 66 cout << "v2:"; 67 output(v2); 68 } 69 70 71 //vector元素旋转移位 72 void test3() { 73 vector<int>v0{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }; 74 cout << "v0:"; 75 output(v0); 76 77 vector<int>v1{ v0 }; 78 rotate(v1.begin(), v1.begin() + 1, v1.end()); 79 cout << "v1:"; 80 output(v1); 81 82 vector<int> v2{ v0 }; 83 rotate(v2.begin(), v2.begin() + 2, v2.end()); 84 cout << "v2: "; 85 output(v2); 86 87 vector<int> v3{ v0 }; 88 rotate(v3.begin(), v3.end() - 1, v3.end()); 89 cout << "v3: "; 90 output(v3); 91 92 vector<int> v4{ v0 }; 93 rotate(v4.begin(), v4.end() - 2, v4.end()); 94 cout << "v4: "; 95 output(v4); 96 97 }
运行结果
任务二
源代码
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 template<typename T> 11 void output(const T& c); 12 13 int rand_int_100(); 14 void test1(); 15 void test2(); 16 17 int main() { 18 cout << "测试1: \n"; 19 test1(); 20 21 cout << "\n测试2: \n"; 22 test2(); 23 } 24 25 //输出容器对象c中的元素 26 template<typename T> 27 void output(const T& c) { 28 for (auto& i : c) 29 cout << i << " "; 30 cout << endl; 31 } 32 33 34 //返回[0,100]内一随机整数 35 int rand_int_100() { 36 return rand() % 101; 37 } 38 39 //赋值并排序 40 void test1() { 41 vector<int>v0(10); 42 generate(v0.begin(), v0.end(), rand_int_100); 43 cout << "v0:"; 44 output(v0); 45 46 vector<int> v1{ v0 }; 47 sort(v1.begin(), v1.end());//默认是升序排序 48 cout << "v1: "; 49 output(v1); 50 51 vector<int>v2{ v0 }; 52 sort(v2.begin() + 1, v2.end() - 1); 53 cout << "v2:"; 54 output(v2); 55 } 56 57 //赋值并求最值和均值 58 void test2() { 59 vector<int>v0(10);//不是{},()是指定vector的大小 60 generate(v0.begin(), v0.end(), rand_int_100); 61 cout << "v0:"; 62 output(v0); 63 64 auto iter1 = min_element(v0.begin(), v0.end()); 65 cout << "最小值: " << *iter1 << endl; 66 67 auto iter2 = max_element(v0.begin(), v0.end()); 68 cout << "最大值: " << *iter2 << endl; 69 70 auto ans = minmax_element(v0.begin(), v0.end()); 71 cout << "最小值：" << *(ans.first) << endl; 72 cout << "最大值：" << *(ans.second) << endl; 73 74 double avg1 = accumulate(v0.begin(), v0.end(), 0) / v0.size(); 75 cout << "均值：" << fixed << setprecision(2) << avg1 << endl; 76 77 cout << endl; 78 vector<int>v1{ v0 }; 79 cout << "v0:"; 80 output(v0); 81 sort(v1.begin(), v1.end()); 82 double avg2 = accumulate(v1.begin() + 1, v1.end() - 1, 0) / (v1.size() - 2); 83 cout << "去掉最大值、最小值之后，均值: " << avg2 << endl; 84 }
运行结果
任务三
源代码
1 #include<iostream> 2 #include<string> 3 #include<algorithm> 4 bool is_palindrome(std::string s); 5 6 int main() 7 { 8 using namespace std; 9 string s; 10 while (cin >> s) 11 cout << boolalpha << is_palindrome(s) << endl; 12 } 13 bool is_palindrome(std::string s) 14 { 15 std::string s0{ s }; 16 reverse(s0.begin(), s0.end()); 17 if (s0 == s) 18 return true; 19 else 20 return false; 21 }
运行结果
任务四
源代码
1 #include <iostream> 2 #include <string> 3 #include <algorithm> 4 5 //用字符串流实现 6 #include<sstream> 7 #include<bitset> 8 9 10 std::string dec2n(int x, int n = 2); 11 12 int main() { 13 using namespace std; 14 int x; 15 while (cin >> x) { 16 cout << "十进制: " << x << endl; 17 cout << "二进制: " << dec2n(x) << endl; 18 cout << "八进制: " << dec2n(x, 8) << endl; 19 cout << "十六进制: " << dec2n(x, 16) << endl << endl; 20 } 21 } 22 23 std::string dec2n(int x, int n) { 24 using namespace std; 25 26 stringstream num; 27 28 //二进制 29 if (n == 2) 30 { 31 num.str("");//清空stringstream 32 num << bitset<8>(x).to_string(); 33 //bitset<int>限制位数，to_string将int类型转化为string 34 //但是多余的0要怎么去掉？ 35 return num.str(); 36 } 37 38 if (n == 8) 39 { 40 num.str(""); 41 num << oct << x;//oct转化为八进制 42 return num.str(); 43 } 44 45 if (n == 16) 46 { 47 num.str(""); 48 num << hex << uppercase << x;//hex十六进制，uppercase大写 49 return num.str(); 50 } 51 }
//可以尝试用栈实现
运行结果
任务五
源代码
1 #include<iostream> 2 #include<vector> 3 #include<string> 4 #include<algorithm> 5 #include<iomanip> 6 7 using namespace std; 8 9 template<typename T> 10 void output(const T& c) { 11 for (auto& i : c) 12 cout << i << " "; 13 cout << endl; 14 } 15 16 void test1(); 17 18 int main() 19 { 20 test1(); 21 return 0; 22 } 23 24 void test1() 25 { 26 //用字符串初始化vector 27 string str1 = "abcdefghijklmnopqrstuvwxyz"; 28 //string str2 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; 29 vector<char> vec1(str1.begin(), str1.end()); 30 //vector<char> vec2(str2.begin(), str2.end()); 31 32 //输出第一列 33 cout << setw(3)<<" "; 34 output(str1); 35 36 //转换为大写字母 37 for (auto& c : vec1) { 38 if (std::islower(c)) { 39 c = toupper(static_cast<unsigned char>(c)); 40 } 41 } 42 int i = 1; 43 for (i = 1; i < 27; i++) 44 { 45 cout <<setw(2)<< i; 46 cout << " "; 47 rotate(vec1.begin(), vec1.begin() + 1, vec1.end()); 48 output(vec1); 49 } 50 }
运行截图
任务六
源代码
1 #include<iostream> 2 #include<random> 3 #include<string> 4 #include<iomanip> 5 6 using namespace std; 7 8 void test(); 9 10 int main() { 11 test(); 12 return 0; 13 } 14 15 void test() { 16 //参考了ai 17 random_device rd;//获取随机数种子 18 mt19937 gen(rd());//随机数生成器 19 20 uniform_int_distribution<>dis(1, 10);//限定范围在1到10 21 22 int correct = 0; 23 24 for (int i = 0; i < 10; i++) { 25 int n1 = dis(gen); 26 int n2 = dis(gen); 27 28 char op=0;//加减乘除 29 int ans=0;//答案 30 31 32 ////如果不能整除 33 //if ((op == '/') && (n1 % n2) != 0) { 34 // do { 35 // n2 = dis(gen); 36 // } while (n1 % n2 != 0); 37 //} 38 39 do { 40 int rad = gen()%4; 41 switch (rad) { 42 case 0:op = '/'; break; 43 case 1:op = '+'; break; 44 case 2:op = '*'; break; 45 case 3:op = '-'; break; 46 } 47 48 //要让n1比n2大 49 if (op == '-') 50 { 51 if (n1 <= n2) { 52 swap(n1, n2); 53 } 54 } 55 } while ((op == '/') && (n1 % n2 != 0)); 56 57 58 59 //计算答案 60 switch (op){ 61 case '+':ans = n1 + n2; break; 62 case'-':ans = n1 - n2; break; 63 case'*':ans = n1 * n2; break; 64 case'/':ans = n1 / n2; break; 65 } 66 67 68 //显示题目，获取答案 69 cout << n1 << " " << op << " " << n2 << " = "; 70 int ans_user; 71 cin >> ans_user; 72 73 74 //判断，统计正确个数 75 if (ans_user == ans)correct++; 76 } 77 78 //输出正确率 79 double crt = static_cast<double>(correct) / 10 * 100; 80 cout << fixed << setprecision(2) << "正确率：" << crt << "%" << endl; 81 }
运行截图(出现➗的概率好小啊）
实验总结
