Looks Rare Raffle
Arrays.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;
 
import {Math} from "@openzeppelin/contracts/utils/math/Math.sol";
 
/**
 * @dev Collection of functions related to array types.
 *      Modified from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/Arrays.sol
 */
library Arrays {
    /**
     * @dev Searches a sorted `array` and returns the first index that contains
     * a value greater or equal to `element`. If no such index exists (i.e. all
     * values in the array are strictly less than `element`), the array length is
     * returned. Time complexity O(log n).
     *
     * `array` is expected to be sorted in ascending order, and to contain no
     * repeated elements.
     */
    function findUpperBound(uint256[] memory array, uint256 element) internal pure returns (uint256) {
        if (array.length == 0) {
            return 0;
        }
 
        uint256 low = 0;
        uint256 high = array.length;
 
        while (low < high) {
            uint256 mid = Math.average(low, high);
 
            // Note that mid will always be strictly less than high (i.e. it will be a valid array index)
            // because Math.average rounds down (it does integer division with truncation).
            if (array[mid] > element) {
                high = mid;
            } else {
                unchecked {
                    low = mid + 1;
                }
            }
        }
 
        // At this point `low` is the exclusive upper bound. We will return the inclusive upper bound.
        if (low > 0 && array[low - 1] == element) {
            unchecked {
                return low - 1;
            }
        } else {
            return low;
        }
    }
}