分别用顺序查找法和折半查找法实现对给定值得查找。

顺序查找法的实现如下：

#include <iostream>
using namespace std;

int seq_search(int arr[], int len, int key) {
    for (int i = 0; i < len; i++) {
        if (arr[i] == key) {
            return i;
        }
    }
    return -1;
}

int main() {
    int arr[] = {1, 3, 5, 7, 9, 11};
    int len = sizeof(arr) / sizeof(arr[0]);
    int key = 7;
    int pos = seq_search(arr, len, key);
    if (pos != -1) {
        cout << "顺序查找成功，元素 " << key << " 在数组中的下标为 " << pos << endl;
    } else {
        cout << "顺序查找失败，元素 " << key << " 不在数组中" << endl;
    }
    return 0;
}

折半查找法的实现如下：

#include <iostream>
using namespace std;

int binary_search(int arr[], int len, int key) {
    int left = 0, right = len - 1;
    while (left <= right) {
        int mid = (left + right) / 2;
        if (arr[mid] == key) {
            return mid;
        } else if (arr[mid] < key) {
            left = mid + 1;
        } else {
            right = mid - 1;
        }
    }
    return -1;
}

int main() {
    int arr[] = {1, 3, 5, 7, 9, 11};
    int len = sizeof(arr) / sizeof(arr[0]);
    int key = 7;
    int pos = binary_search(arr, len, key);
    if (pos != -1) {
        cout << "折半查找成功，元素 " << key << " 在数组中的下标为 " << pos << endl;
    } else {
        cout << "折半查找失败，元素 " << key << " 不在数组中" << endl;
    }
    return 0;
}