2022.12.4-----leetcode.1774

  int res;
 
    public int closestCost(int[] baseCosts, int[] toppingCosts, int target) {
        res = Arrays.stream(baseCosts).min().getAsInt();
        for (int b : baseCosts) {
            dfs(toppingCosts, 0, b, target);
        }
        return res;
    }
 
    public void dfs(int[] toppingCosts, int p, int curCost, int target) {
        if (Math.abs(res - target) < curCost - target) {
            return;//成本大于目标
        } else if (Math.abs(res - target) >= Math.abs(curCost - target)) {
            if (Math.abs(res - target) > Math.abs(curCost - target)) {
                res = curCost;//当前成本更靠近目标
            } else {
                res = Math.min(res, curCost);//成本相同，取较小值
            }
        }
        if (p == toppingCosts.length)
            return;//到达边界
        //对当前配料递归三种选择
        dfs(toppingCosts, p + 1, curCost + toppingCosts[p] * 2, target);
        dfs(toppingCosts, p + 1, curCost + toppingCosts[p], target);
        dfs(toppingCosts, p + 1, curCost, target);
    }