不是把孩子送进培训流水线，
而是带他走进真正的计算机世界。

#include <iostream>
#include <vector>
using namespace std;

int binarySearch(const vector<int>& nums, int target) {
    int left = 0, right = nums.size() - 1;
    while (left <= right) {
        int mid = left + (right - left) / 2;
        if (nums[mid] == target) return mid;
        if (nums[mid] < target) left = mid + 1;
        else right = mid - 1;
    }
    return -1;
}