C++

#include <iostream>
#include <vector>

using namespace std;

void binary_search(vector<int> &nums, int n, int k)
{
    int left = 0, right = n-1;
    while (left < right) {
        int middle = left + ((right - left) >> 1);
        if (nums[middle] < k)
            left = middle + 1;
        else
            right = middle;
    }
    if (left == n || nums[left] != k) {
        cout << -1 << " " << -1 << endl;
        return;
    }
    int l = left, r = n;
    while (l+1 < r) {
        int mid = l + ((r-l) >> 1);
        if (nums[mid] <= k)
            l = mid;
        else
            r = mid;
    }
    cout << left << ' ' << l << endl;
}

int main()
{
    int n, q; cin >> n >> q;
    vector<int> nums(n);
    for (int i = 0; i < n; i ++)
        cin >> nums[i];
    while (q --) {
        int k; cin >> k;
        binary_search(nums, n, k);
    }
    return 0;
}

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

void binary_search(vector<int> &nums, int n, int k)
{
    auto left=lower_bound(nums.begin(), nums.end(), k);
    auto right=upper_bound(nums.begin(), nums.end(), k);
    if(left == nums.end() || *left!=k) cout << -1 << " " << -1 << endl;
    else cout << (int)(left-nums.begin()) << " " << (int)(right-nums.begin()-1) << endl;
}

int main()
{
    int n, q; cin >> n >> q;
    vector<int> nums(n);
    for (int i = 0; i < n; i ++)
        cin >> nums[i];
    while (q --) {
        int k; cin >> k;
        binary_search(nums, n, k);
    }
    return 0;
}

Python

from bisect import *

n, q = map(int, input().split())
lst = list(map(int, input().split()))
for _ in range(q):
    k = int(input())
    l = bisect_left(lst, k)
    r = bisect_right(lst, k)
    if l == len(lst) or lst[l] != k:
        print("-1 -1")
    else:
        print(l, r-1)