0034-find-first-and-last-position-of-element-in-sorted-array.cpp

class Solution {
public:
    vector<int> searchRange(vector<int>& nums, int target) {
        vector<int> ans;
        int a = lower_bound(nums.begin(), nums.end(), target) - nums.begin();
        int b = upper_bound(nums.begin(), nums.end(), target) - nums.begin()-1;
        if(a>b)  return {-1,-1};
        return {a,b};
    }
};