利用指针将最小数与第一个数调换，最大数与最后一个数对换

以下是利用指针将最小数与第一个数调换，最大数与最后一个数对换的C++代码实现：

#include <iostream>
using namespace std;

void swap(int *xp, int *yp) {
    int temp = *xp;
    *xp = *yp;
    *yp = temp;
}

void swapMinMax(int arr[], int n) {
    int min_idx = 0, max_idx = 0;
    for (int i = 1; i < n; i++) {
        if (arr[i] < arr[min_idx]) {
            min_idx = i;
        }
        if (arr[i] > arr[max_idx]) {
            max_idx = i;
        }
    }
    swap(&arr[0], &arr[min_idx]);
    swap(&arr[n-1], &arr[max_idx]);
}

int main() {
    int arr[] = {3, 5, 2, 7, 6, 4, 1};
    int n = sizeof(arr)/sizeof(arr[0]);

    << "Original array: ";
    for (int i = 0; i < n; i++) {
        cout << arr[i] << " ";
    }

    swapMinMax(arr, n);

    cout << "\nArray after swapping min and max: ";
    for (int i = 0; i < n; i++) {
        cout << arr[i] << " ";
    }

    return 0;
}