c++ for循环有意思的代码

以下是一些有趣的C++ for循环代码：
1. 倒序输出数组元素：

int arr[5] = {1, 2, 3, 4, 5};
for (int i = 4; i >= 0; i--) {
    cout << arr[i] << " ";
}

2. 输出九九乘法表：

for (int i = 1; i <= 9; i++) {
    for (int j = 1; j <= i; j++) {
        cout << j << "x" << i << "=" << i*j << " ";
    }
    cout << endl;
}

3. 输出斐波那契数列前n项：

int n = 10;
int a = 0, b = 1, c;
for (int i = 1; i <= n; i++) {
    cout << a << " ";
    c = a + b;
    a = b;
    b = c;
}