less than O(n+m)?

derp.js

var all_items = [{
  "name": "cat",
  "id": 1
}, {
  "name": "dog",
  "id": 2
}, {
  "name": "spoon",
  "id": 3
}, {
  "name": "ninja",
  "id": 4
}];

var special_items_names = ["cat", "spoon"];

for (var n = 0, lenA = all_items.length; n < lenA; n++) {
    for (var lenB = special_items_names.length, i = lenB-1; i >= 0; i--) {
        if (all_items[n].name === special_items_names[i]) {
            all_items[n].special = true;
            special_items_names.pop();
            break;
        }
    }
});