实验1
代码1
#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{ v0 };
rotate(v2.begin(), v2.begin()+2, v2.end());
cout << "v2:";output(v2);
vector<int> v3{ v0 };
rotate(v3.begin(), v3.begin()-1, v3.end());
cout << "v3:";output(v3);
vector<int> v4{ v0 };
rotate(v4.begin(), v4.begin()-2, v4.end());
cout << "v4:";output(v4);
}
问题1回答：reverse是将s0直接调转，reverse_copy是将s0的调转结果放到s2中。
问题2回答：起始元素位置，结尾元素位置，移动的方向和步数。
运行结果截图
代码2
include
include
include
include
include
include
include
// 模板函数声明
template
void output(const T& c);
int generate_random_number();
void test1();
void test2();
int main() {
std::srand(std::time(0)); // 添加随机种子
std::cout << "测试1: \n";
test1();
std::cout << "\n测试2: \n";
test2();
}
// 输出容器对象c中的元素
template
void output(const T& c) {
for (auto& i : c)
std::cout << i << ' ';
std::cout << '\n';
}
// 返回[0, 100]区间内的一个随机整数
int generate_random_number() {
return std::rand() % 101;
}
// 测试1:对容器类对象指定迭代器区间赋值?排序
void test1() {
using namespace std;
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(), generate_random_number); // 生成随机数填充v0
cout << "v0: "; output(v0);
vector<int> v1{ v0 };
sort(v1.begin(), v1.end()); // 对整个vector排序
cout << "v1: "; output(v1);
vector<int> v2{ v0 };
sort(v2.begin() + 1, v2.end() - 1); // 只对中间部分排序,不包含首尾元素
cout << "v2: "; output(v2);
}
// 测试2:对容器类对象指定迭代器区间赋值?计算最大值/最小值/均值
void test2() {
using namespace std;
vector<int> v0(10);
generate(v0.begin(), v0.end(), generate_random_number);
cout << "v0: "; output(v0);
// 求最大值和最小值
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;
// 同时求最大值和最小值
auto ans = minmax_element(v0.begin(), v0.end());
cout << "最小值: " << *(ans.first) << endl;
cout << "最大值: " << *(ans.second) << endl;
// 求平均值
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;
}
回答1：随机生成范围内数字
回答2：效率更高，代码更简洁
回答3：效果相同
运行结果：
代码3
include
include
include
include
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';
}
回答1：将字母移动一位
回答2：tolower将字母小写toupper将字母大写
回答3：第一个起始位置，第二个终止位置，转移的位置，变换调用的函数，
会覆盖s1.
运行结果：
代码4
include
include
include
bool is_palindrome(const std::string& s);
bool is_palindrome_ignore_case(const std::string& s);
int main() {
using namespace std;
string s;
// 多组输入，直到按下Ctrl+Z结束测试
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";
}
return 0;
}
bool is_palindrome(const std::string& s)
{
int i=0;
int j=s.size()-1;
while (i < j)
{
if (s[i] != s[j])
{
return 0;
}
i++;
j--;
}
return 1;
}
bool is_palindrome_ignore_case(const std::string& s)
{
int i = 0;
int j = s.size() - 1;
while (i < j)
{
if (tolower(s[i])!=tolower(s[j]))
{
return 0;
}
i++;
j--;
}
return 1;
}
回答1：将cin >> s替换为getline(cin,s)
代码5
include
include
include
using namespace std;
string dec2n(int x, int n = 2);
int main()
{
int x;
while (cin >> x)
{
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";
}
return 0;
}
string dec2n(int x, int n)
{
if (x == 0)
{
return "0";
}
int a = x;
vector<int> c;
while (a != 0)
{
int d = a % n;
a = a / n;
c.push_back(d);
}
string e;
for (int i = c.size() - 1; i >= 0; --i)
{
int d = c[i];
if (d >= 10)
{
e += static_cast<char>(d + 55);
}
else
{
e += static_cast<char>(d + '0');
}
}
return e;
}
回答1：
代码6
include
include
using namespace std;
int main()
{
cout << " ";
for (char c = 'a'; c <= 'z'; c++)
{
cout << c << " ";
}
cout << endl;
for (int i = 1; i <= 26; i++)
{
cout << setw(2) << i << " ";
for (char c = 'A'; c <= 'Z'; c++)
{
char cipher = 'A' + (c - 'A' + i) % 26;
cout << cipher << " ";
}
cout << endl;
}
return 0;
}
代码7
include
include
include
include
using namespace std;
int main() {
// 设置随机数种子，使每次运行生成不同的随机数
srand(static_cast
int correctCount = 0;
// 生成 10 道题
for (int i = 0; i < 10; i++) {
int num1 = rand() % 10 + 1; // 第一个操作数，范围 [1,10]
int num2 = rand() % 10 + 1; // 第二个操作数，范围 [1,10]
int op = rand() % 4; // 随机选择运算符，0:加，1:减，2:乘，3:除
// 处理减法，确保第一个操作数大于等于第二个操作数
if (op == 1) {
if (num1 < num2) {
swap(num1, num2);
}
}
// 处理除法，确保第一个操作数能被第二个操作数整除
else if (op == 3) {
// 确保第二个操作数不为 0，且能整除
while (num2 == 0 || num1 % num2 != 0) {
num1 = rand() % 10 + 1;
num2 = rand() % 10 + 1;
}
}
int userAnswer, correctAnswer;
char opChar;
// 根据运算符计算正确答案并输出题目
switch (op) {
case 0:
opChar = '+';
correctAnswer = num1 + num2;
cout << num1 << " " << opChar << " " << num2 << " = ";
break;
case 1:
opChar = '-';
correctAnswer = num1 - num2;
cout << num1 << " " << opChar << " " << num2 << " = ";
break;
case 2:
opChar = '*';
correctAnswer = num1 * num2;
cout << num1 << " " << opChar << " " << num2 << " = ";
break;
case 3:
opChar = '/';
correctAnswer = num1 / num2;
cout << num1 << " " << opChar << " " << num2 << " = ";
break;
}
// 用户输入答案
cin >> userAnswer;
// 判断答案是否正确
if (userAnswer == correctAnswer) {
correctCount++;
}
}
// 计算并输出正确率
double accuracy = static_cast<double>(correctCount) / 10 * 100;
cout << "正确率: " << fixed << setprecision(2) << accuracy << "%" << endl;
return 0;
}
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