请用C++写一个顺序查找和折半查找

顺序查找（线性查找）：

#include <iostream>
using namespace std;

int seqSearch(int arr[], int n, int x) {
    for (int i = 0; i < n; i++) {
        if (arr[i] == x) {
            return i;
        }
    }
    return -1;
}

int main() {
    int arr[] = {2, 3, 5, 7, 11, 13, 17, 19};
    int n = sizeof(arr) / sizeof(arr[0]);
    int x = 11;
    int index = seqSearch(arr, n, x);
    if (index != -1) {
        cout << "Found at index " << index << endl;
    } else {
        cout << "Not found" << endl;
    }
    return 0;
}

折半查找（二分查找）：

#include <iostream>
using namespace std;

int binarySearch(int arr[], int n, int x) {
    int left = 0, right = n - 1;
    while (left <= right) {
        int mid = (left + right) / 2;
        if (arr[mid] == x) {
            return mid;
        } else if (arr[mid] > x) {
            right = mid - 1;
        } else {
            left = mid + 1;
        }
    }
    return -1;
}

int main() {
    int arr[] = {2, 3, 5, 7, 11, 13, 17, 19};
    int n = sizeof(arr) / sizeof(arr[0]);
    int x = 11;
    int index = binarySearch(arr, n, x);
    if (index != -1) {
        cout << "Found at index " << index << endl;
    } else {
        cout << "Not found" << endl;
    }
    return 0;
}