Solidity
你能得到一個隨機數數組嗎?
這個問題說明了一切。我可以得到一組可靠的隨機數嗎?
由於區塊鍊是確定性的,因此獲得一個可靠的隨機數本身就很棘手。你會想要到達區塊鏈之外,但只能使用可以證明它們的數字是隨機的服務。為此,您需要使用Chainlink VRF並返回整個數組。
然後,您可以創建一個
expand
函式,即基於種子隨機數的整個隨機數數組。function expand(uint256 randomValue, uint256 n) public pure returns (uint256[] memory expandedValues) { expandedValues = new uint256[](n); for (uint256 i = 0; i < n; i++) { expandedValues[i] = uint256(keccak256(abi.encode(randomValue, i))); } return expandedValues; }
就上下文而言,這是 kovan 測試網上的完整合約的樣子:
pragma solidity 0.6.6; import "@chainlink/contracts/src/v0.6/VRFConsumerBase.sol"; /** * THIS IS AN EXAMPLE CONTRACT WHICH USES HARDCODED VALUES FOR CLARITY. * PLEASE DO NOT USE THIS CODE IN PRODUCTION. */ contract RandomNumberConsumer is VRFConsumerBase { bytes32 internal keyHash; uint256 internal fee; uint256 public randomResult; /** * Constructor inherits VRFConsumerBase * * Network: Kovan * Chainlink VRF Coordinator address: 0xdD3782915140c8f3b190B5D67eAc6dc5760C46E9 * LINK token address: 0xa36085F69e2889c224210F603D836748e7dC0088 * Key Hash: 0x6c3699283bda56ad74f6b855546325b68d482e983852a7a82979cc4807b641f4 */ constructor() VRFConsumerBase( 0xdD3782915140c8f3b190B5D67eAc6dc5760C46E9, // VRF Coordinator 0xa36085F69e2889c224210F603D836748e7dC0088 // LINK Token ) public { keyHash = 0x6c3699283bda56ad74f6b855546325b68d482e983852a7a82979cc4807b641f4; fee = 0.1 * 10 ** 18; // 0.1 LINK (Varies by network) } /** * Requests randomness */ function getRandomNumber() public returns (bytes32 requestId) { require(LINK.balanceOf(address(this)) >= fee, "Not enough LINK - fill contract with faucet"); return requestRandomness(keyHash, fee); } /** * Callback function used by VRF Coordinator */ function fulfillRandomness(bytes32 requestId, uint256 randomness) internal override { randomResult = randomness; } // function withdrawLink() external {} - Implement a withdraw function to avoid locking your LINK in the contract function expand(uint256 randomValue, uint256 n) public pure returns (uint256[] memory expandedValues) { expandedValues = new uint256[](n); for (uint256 i = 0; i < n; i++) { expandedValues[i] = uint256(keccak256(abi.encode(randomValue, i))); } return expandedValues; } }