通关游戏所需的最低生命值

/*
 * Two Sum Solution in Java using Streams
 * Approach: Streams with Collectors to Map
 * - Use streams to iterate through the array
 * - Collect the elements into a map with the complement as key and index as value
 * - Find the first element in the array whose complement exists in the map
 */
import java.util.HashMap;
import java.util.stream.IntStream;

public class TwoSumStream {
    public int[] twoSum(int[] nums, int target) {
        HashMap<Integer, Integer> map = new HashMap<>();
        return IntStream.range(0, nums.length)
                        .mapToObj(i -> new int[] {i, nums[i]})
                        .filter(pair -> {
                            int complement = target - pair[1];
                            if (map.containsKey(complement)) {
                                return true;
                            }
                            map.put(pair[1], pair[0]);
                            return false;
                        })
                        .map(pair -> new int[] {map.get(target - pair[1]), pair[0]})
                        .findFirst()
                        .orElseThrow(() -> new IllegalArgumentException("No two sum solution"));
    }
}