二分法程序(C++)的错误答案

#include <iostream>
using namespace std;

int binarySearch(int arr[], int target, int left, int right) {
    while (left <= right) {
        int mid = left + (right - left) / 2;
        if (arr[mid] == target) {
            return mid;
        }
        else if (arr[mid] < target) {
            left = mid + 1;
        }
        else {
            right = mid - 1;
        }
    }
    return -1; // 目标元素不存在
}

int main() {
    int arr[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
    int target = 6;
    int size = sizeof(arr) / sizeof(arr[0]);
    int result = binarySearch(arr, target, 0, size - 1);
    if (result == -1) {
        cout << "目标元素不存在" << endl;
    }
    else {
        cout << "目标元素位于索引 " << result << endl;
    }
    return 0;
}