示例 1: Hello World
#include
using namespace std;
int main() {
cout << "Hello, World!" << endl;
return 0;
}
示例 2: 计算两个数的和
#include
using namespace std;
int main() {
int a = 5;
int b = 10;
int sum = a + b;
cout << "Sum is: " << sum << endl;
return 0;
}
示例 3: 使用函数计算阶乘
#include
using namespace std;
int factorial(int n) {
if (n <= 1) return 1;
return n * factorial(n - 1);
}
int main() {
int num = 5;
cout << "Factorial of " << num << " is " << factorial(num) << endl;
return 0;
}
示例 4: 打印Fibonacci序列
#include
using namespace std;
void printFibonacci(int n) {
int t1 = 0, t2 = 1;
cout << t1 << " " << t2 << " ";
for (int i = 2; i <= n; ++i) {
int next = t1 + t2;
cout << next << " ";
t1 = t2;
t2 = next;
}
}
int main() {
int n = 10;
printFibonacci(n);
return 0;
}
示例 5: 检查一个数是否为素数
#include
using namespace std;
bool isPrime(int n) {
if (n <= 1) return false;
for (int i = 2; i * i <= n; i++) {
if (n % i == 0) return false;
}
return true;
}
int main() {
int num = 11;
if (isPrime(num)) {
cout << num << " is a prime number." << endl;
} else {
cout << num << " is not a prime number." << endl;
}
return 0;
}
示例 6: 计算圆的面积
#include
#include
using namespace std;
double circleArea(double r) {
return M_PI * pow(r, 2);
}
int main() {
double radius = 5.0;
cout << "Area of the circle is: " << circleArea(radius) << endl;
return 0;
}
示例 7: 排序数组
#include
#include
using namespace std;
int main() {
int arr[] = {5, 3, 8, 4, 2};
int n = sizeof(arr)/sizeof(arr[0]);
sort(arr, arr+n);
for (int i = 0; i < n; ++i) {
cout << arr[i] << " ";
}
cout << endl;
return 0;
}
示例 8: 字符串反转
#include
#include
using namespace std;
int main() {
string str = "hello";
reverse(str.begin(), str.end());
cout << "Reversed string is: " << str << endl;
return 0;
}
示例 9: 数组查找
#include
#include
using namespace std;
int findNumber(vector& vec, int target) {
for (int i = 0; i < vec.size(); ++i) {
if (vec[i] == target) return i;
}
return -1;
}
int main() {
vector vec = {1, 2, 3, 4, 5};
int target = 3;
int index = findNumber(vec, target);
if (index != -1) {
cout << "Element found at index: " << index << endl;
} else {
cout << "Element not found." << endl;
}
return 0;
}
示例 10: 从字符串中删除特定字符
#include
#include
using namespace std;
string removeChar(string s, char c) {
string result = "";
for (char ch : s) {
if (ch != c) result += ch;
}
return result;
}
int main() {
string str = "example string";
char ch = 'e';
cout << "Original string: " << str << endl;
cout << "String after removing '" << ch << "': " << removeChar(str, ch) << endl;
return 0;
}
示例 11: 输出正三角形
#include
using namespace std;
void printTriangle(int n) {
for (int i = 0; i < n; ++i) {
// 打印空格
for (int j = 0; j < n - i - 1; ++j) {
cout << " ";
}
// 打印星号
for (int k = 0; k < 2 * i + 1; ++k) {
cout << "*";
}
cout << endl;
}
}
int main() {
int n = 5;
printTriangle(n);
return 0;
}
示例 12: 输出倒三角形
#include
using namespace std;
void printReverseTriangle(int n) {
for (int i = n; i > 0; --i) {
// 打印空格
for (int j = 0; j < n - i; ++j) {
cout << " ";
}
// 打印星号
for (int k = 0; k < 2 * i - 1; ++k) {
cout << "*";
}
cout << endl;
}
}
int main() {
int n = 5;
printReverseTriangle(n);
return 0;
}
示例 13: 斐波那契数列（迭代版）
#include
using namespace std;
void fibonacci(int n) {
int t1 = 0, t2 = 1;
cout << t1 << " " << t2 << " ";
for (int i = 2; i < n; ++i) {
int next = t1 + t2;
cout << next << " ";
t1 = t2;
t2 = next;
}
}
int main() {
int n = 10;
fibonacci(n);
return 0;
}
示例 14: 求解一元二次方程
#include
#include
using namespace std;
void solveQuadraticEquation(double a, double b, double c) {
double discriminant = b * b - 4 * a * c;
if (discriminant < 0) {
cout << "No real roots" << endl;
} else {
double root1 = (-b + sqrt(discriminant)) / (2 * a);
double root2 = (-b - sqrt(discriminant)) / (2 * a);
cout << "Roots are: " << root1 << " and " << root2 << endl;
}
}
int main() {
solveQuadraticEquation(1, -3, 2);
return 0;
}
示例 15: 判断一个数是否为回文数
#include
using namespace std;
bool isPalindrome(int x) {
int original = x, reversed = 0;
while (x > 0) {
reversed = reversed * 10 + x % 10;
x /= 10;
}
return original == reversed;
}
int main() {
int num = 121;
if (isPalindrome(num)) {
cout << num << " is a palindrome." << endl;
} else {
cout << num << " is not a palindrome." << endl;
}
return 0;
}
示例 16: 输出杨辉三角
#include
using namespace std;
void printPascalTriangle(int n) {
for (int line = 1; line <= n; ++line) {
int C = 1;
for (int i = 1; i <= line; ++i) {
cout << C << " ";
C = C * (line - i) / i;
}
cout << endl;
}
}
int main() {
int n = 5;
printPascalTriangle(n);
return 0;
}
示例 17: 模拟投掷骰子
#include
#include
#include
using namespace std;
int rollDice() {
srand(time(nullptr));
return rand() % 6 + 1;
}
int main() {
int dice = rollDice();
cout << "Rolled dice: " << dice << endl;
return 0;
}
示例 18: 计算平均值
#include
using namespace std;
double calculateAverage(int arr[], int size) {
int sum = 0;
for (int i = 0; i < size; ++i) {
sum += arr[i];
}
return static_cast(sum) / size;
}
int main() {
int arr[] = {10, 20, 30, 40, 50};
int size = sizeof(arr) / sizeof(arr[0]);
double avg = calculateAverage(arr, size);
cout << "Average: " << avg << endl;
return 0;
}
示例 19: 生成随机数序列
#include
#include
#include
using namespace std;
void generateRandomNumbers(int arr[], int size) {
srand(time(nullptr));
for (int i = 0; i < size; ++i) {
arr[i] = rand() % 100;
}
}
int main() {
int arr[10];
generateRandomNumbers(arr, 10);
for (int i = 0; i < 10; ++i) {
cout << arr[i] << " ";
}
cout << endl;
return 0;
}
示例 20: 字符串拼接
#include
#include
using namespace std;
string concatenateStrings(const string& s1, const string& s2) {
return s1 + " " + s2;
}
int main() {
string s1 = "Hello";
string s2 = "World";
cout << "Concatenated string: " << concatenateStrings(s1, s2) << endl;
return 0;
}
