编辑代码

#include <iostream>
#include <vector>

using namespace std;

int binsearch(const vector<int>& nums, int target) {
    int left = 0;
    int right = nums.size()-1;

    while (left <= right){
        int mid = left + (right - left)/2;
        if (nums[mid] == target){
             return mid;
        }
        else if (nums[mid]<target){
            left = mid + 1;
        }
        else{
            right = mid -1;
        }
    }
    return -1;
}



int main() {
    
    vector<int> nums;
    int num;

    while (cin >> num) {
        nums.push_back(num);
        if (cin.peek() == '\n') { 
            break;
        }
    }

    int target = nums.back();
    nums.pop_back(); 

    cout << binsearch(nums, target) << endl; // 输出目标值的下标
    return 0;
}