binary_search

#include <iostream>
#include <vector>

using namespace std;

int binarySearch(vector<int>& arr, int target) {
    int left = 0;
    int right = arr.size() - 1;

    while (right - left > 1) {
        int mid = left + (right - left) / 2;

        if (arr[mid] == target) {
            return mid;
        } else if (arr[mid] < target) {
            left = mid;
        } else {
            right = mid;
        }
    }

    if (arr[left] == target) {
        return left;
    } else if (arr[right] == target) {
        return right;
    } else {
        return -1; // Элемент не найден
    }
}

int main() {
    vector<int> arr = {1, 3, 5, 7, 9, 11, 13};
    int target = 7;
    int result = binarySearch(arr, target);
    if (result != -1) {
        cout << "Элемент найден в позиции: " << result << endl;
    } else {
        cout << "Элемент не найден." << endl;
    }
    return 0;
}