setting up erc721a

remappings.txt

@@ -1,3 +1,4 @@
 ds-test/=lib/solmate/lib/ds-test/src/
 solmate/=lib/solmate/src/
-forge-std/=lib/forge-std/src/
+forge-std/=lib/forge-std/src/
+erc721a/=lib/erc721a/contracts/

src/Unaboomer.sol

@@ -10,12 +10,12 @@ BOMB holders can randomly mail bombs to other owners
 chaos ensues until 1000 survivors - the game stops
 ********/
 
-import {ERC721} from "solmate/tokens/ERC721.sol";
+import {ERC721A} from "erc721a/ERC721A.sol";
 import {Owned} from "solmate/auth/Owned.sol";
 import {LibString} from "solmate/utils/LibString.sol";
 import {Main} from "./Main.sol";
 
-contract Unaboomer is ERC721, Owned {
+contract Unaboomer is ERC721A, Owned {
     using LibString for uint256;
 
     mapping(uint256 => bool) public tokenDead;
@@ -28,7 +28,7 @@ contract Unaboomer is ERC721, Owned {
     string public deadURI;
     Main public main;
 
-    constructor() ERC721("Unaboomer", "BOOMR") Owned(msg.sender) {}
+    constructor() ERC721A("Unaboomer", "BOOMR") Owned(msg.sender) {}
 
     // =========================================================================
     //                              Admin
@@ -70,30 +70,19 @@ contract Unaboomer is ERC721, Owned {
 
     /// Mint tokens from main contract
     function radicalize(address _to, uint256 _amount) external payable onlyMain {
-        require(minted + _amount <= MAX_SUPPLY, "supply reached");
-        unchecked {
-            uint256 startToken = minted + 1;
-            for (uint256 i; i < _amount; i++) {
-                _mint(_to, startToken);
-                startToken += 1;
-            }
-            minted += _amount;
-        }
+        require(totalSupply() + _amount <= MAX_SUPPLY, "supply reached");
+        _safeMint(_to, _amount);
     }
 
     /// Toggle token state from living to dead
     function kill(uint256 tokenId) external onlyMain {
-        require(tokenId < minted, "invalid token id");
+        require(tokenId <= totalSupply(), "invalid token id");
         if (tokenDead[tokenId] == false) {
             killCount++;
             tokenDead[tokenId] = true;
         }
     }
 
-    function totalSupply() public view returns (uint256 supply) {
-        return minted;
-    }
-
     function tokenURI(uint256 _tokenId) public view override returns (string memory) {
         if (tokenDead[_tokenId]) {
             return string(abi.encodePacked(deadURI, _tokenId.toString(), ".json"));
@@ -102,7 +91,7 @@ contract Unaboomer is ERC721, Owned {
         }
     }
 
-    function supportsInterface(bytes4 interfaceId) public view virtual override (ERC721) returns (bool) {
+    function supportsInterface(bytes4 interfaceId) public view virtual override (ERC721A) returns (bool) {
         return super.supportsInterface(interfaceId);
     }
 }