Function calculate

javascript/0494-target-sum.js:64–91

(
    nums,
    target,
    total,
    index = 0,
    sum = 0,
    memo = initMemo(nums, total),
)

        ); /* Time O(M) | Space O(M) */

const calculate = (
    nums,
    target,
    total,
    index = 0,
    sum = 0,
    memo = initMemo(nums, total),
) => {
    const isBaseCase = index === nums.length;
    if (isBaseCase) {
        const isTarget = sum === target;
        if (isTarget) return 1;

        return 0;
    }

    const hasSeen = memo[index][sum + total] != null;
    if (hasSeen) return memo[index][sum + total];

    return dfs(
        nums,
        target,
        total,
        index,
        sum,
        memo,
    ); /* Time O(N * M) | Space O((N * M) + HEIGHT) */
};

var dfs = (nums, target, total, index, sum, memo) => {
    const left = calculate(