实验一 现代C++编程初体验

case 1:

// 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);
}

 

case 2:

#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10generate(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;
}

 

case 3:

#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
// 待补足
// ×××
bool is_palindrome(std::string s)
{int n;n=s.length();for(int i=0;i<n/2;i++){if(s[i]!=s[n-i-1]){return false;}}return true;
}

 

case 4:

#include <iostream>
#include <string>
#include <algorithm>
#include <sstream>
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
// 待补足
// ×××
std::string dec2n(int x,int n)
{std::string s="";std::stringstream ss;switch(n){case 2:{while (x > 0){s = std::to_string(x % 2) + s;x = x / 2;}if (x == 0)s = std::to_string(0);return s;}case 8:{ss<<std::oct<<x;s=ss.str();return s;    break;}case 16:{ss<<std::hex<<x;s=ss.str();return s;    break;}}
}

 

case 5:

#include<iostream>
#include<string>
#include<iomanip>
using namespace std;
int main()
{char a;cout << setw(2)<<' ';for (int i = 0; i < 26; i++){a = 'a' + i;cout << setw(2) << a;}cout << endl;for (int i = 1; i <= 26; i++){cout << setw(2) << i;for (int j = 0; j < 26; j++){int t = (i + j) % 26;a = 'A' + t;cout << setw(2) <<a;}cout << endl;}return 0;
}

 

case 6:

#include<iostream>
#include<string>
#include<random>
#include<iomanip>
using namespace std;
int main()
{std::random_device rd;std::mt19937 gen(rd());int t=0, r0, r1, r2,x;char f[4] = { '+','-','*','/' };for (int i = 0; i < 10; i++){std::uniform_int_distribution<int> dis0(0,3);r0 = dis0(gen);switch (r0){case 1:{std::uniform_int_distribution<int> dis1(2, 10);r1 = dis1(gen);std::uniform_int_distribution<int> dis2(1, r1-1);r2 = dis2(gen);cout << r1 << f[r0] << r2 << '=';cin >> x;if (x == r1 - r2)t++;break;}case 3:{std::uniform_int_distribution<int> dis3(1, 10);r1 = dis3(gen);std::uniform_int_distribution<int> dis4(1, 10/r1);r2 = dis4(gen);int l = r1 * r2;cout << l << f[r0] << r1<<'=';cin >> x;if (x == r2)t++;break;}default:{std::uniform_int_distribution<int> dis5(1, 10);r1 = dis5(gen);r2 = dis5(gen);cout << r1 << f[r0] << r2<<'=';cin >> x;if ((r0==0&&x==r1+r2)||(r0==2&&x==r1*r2))t++;break;}}}t = t * 10;cout << "正确率："<<setprecision(2)<<t<<"%" << endl;return 0;
}