实验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);
}
实验任务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10
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
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;
}
实验任务3：
#include <string>
#include <algorithm>
bool is_palindrome(std::string s)
{
int len=s.size();
for(int i=0;i<len;i++)
{
if(s[i]!=s[len-1-i])
{
return false;
}
else
{
return true;
}
}
}
int main() {
using namespace std;
string s;
while(cin >> s)
cout << boolalpha << is_palindrome(s) << endl;
}
实验任务4：
#include <iostream>
#include <iostream>
#include <string>
#include <algorithm>
std::string dec2n(int x, int n = 2) {
if (x == 0) return "0";
std::string result;
bool isNegative = x < 0;
x = std::abs(x);
while (x > 0) {
int remainder = x % n;
if (remainder < 10) {
result += (remainder + '0');
} else {
result += (remainder - 10 + 'A');
}
x /= n;
}
if (isNegative && n == 10) {
result += '-';
}
std::reverse(result.begin(), result.end());
return result;
}
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;
}
}
实验任务5：
#include <iostream>
#include <iomanip>
int main() {
std::cout << " a b c d e f g h i j k l m n o p q r s t u v w x y z" << std::endl;
for (int i = 1; i <= 26; ++i) {
std::cout << std::setw(2) << i << " ";
for (int j = 0; j < 26; ++j) {
char letter = 'A' + (j + i - 1) % 26;
std::cout << letter<<" ";
}
std::cout << std::endl;
}
return 0;
}
实验任务6：
#include <iostream>
#include <cstdlib>
#include <ctime>
#include <iomanip>
using namespace std;
void generateQuestion(int &a, int &b, char &op) {
int operation = rand() % 4;
switch (operation) {
case 0:
a = rand() % 10 + 1;
b = rand() % 10 + 1;
op = '+';
break;
case 1:
b = rand() % 9 + 1;
a = b + (rand() % (10 - b + 1));
op = '-';
break;
case 2:
a = rand() % 10 + 1;
b = rand() % 10 + 1;
op = '*';
break;
case 3:
b = rand() % 9 + 1;
a = b * (rand() % 10 + 1);
op = '/';
break;
}
}
int main() {
srand(static_cast<unsigned int>(time(0)));
int correctCount = 0;
const int totalQuestions = 10;
for (int i = 0; i < totalQuestions; ++i) {
int a, b;
char op;
generateQuestion(a, b, op);
int correctAnswer;
switch (op) {
case '+':
correctAnswer = a + b;
break;
case '-':
correctAnswer = a - b;
break;
case '*':
correctAnswer = a * b;
break;
case '/':
correctAnswer = a / b;
break;
}
cout << a << " " << op << " " << b << " = ";
int userAnswer;
cin >> userAnswer;
if (userAnswer == correctAnswer) {
correctCount++;
}
}
double accuracy = (static_cast<double>(correctCount) / totalQuestions) * 100;
cout << fixed << setprecision(2);
cout << "正确率： " << accuracy << "%" << endl;
return 0;
}
