377. Combination Sum IV

class Solution {
    public int combinationSum4(int[] nums, int target) {
        // 定义 dp[i] 为总和为 i 的元素组合的个数
        int[] dp = new int[target + 1];
        dp[0] = 1;

        for (int i = 1; i <=target; i++) {
            for (int num : nums) {
                if (i - num >= 0) {
                    dp[i] += dp[i - num];
                }
            }
        }

        return dp[target];
    }
}