Javascript 硬币兑换运行超时

我想解决零钱的问题.我使用了两段类似的代码，但结果是一段通过，而另一段运行超时.我想知道为什么这两段类似的代码有两个不同的结果，请解释一下原理.

这个问题的leetcode链接: https://leetcode.cn/problems/coin-change/description/

超过时限的输入是:

币= [186 419，83，408]

金额= 6249

1.通过一:

var coinChange = function(coins, amount) {
    const filter = amount + 1;
    const memo = new Array(amount + 1).fill(filter);
    const dp = function(coins, amount) {
        if (amount === 0) {
            return 0;
        }
        if (amount < 0) {
            return -1;
        }
        if (memo[amount] !== filter) {
            return memo[amount];
        }
        let res = Infinity;
        for (let coin of coins) {
            let subAmount = dp(coins, amount - coin);
            if (subAmount === -1) {
                continue;
            }
            res = Math.min(res, subAmount + 1);
        }
        memo[amount] = (res === Infinity) ? -1 : res;
        return memo[amount];
    }
    return dp(coins, amount);
}

2. 一次运行超时:

var coinChange = function(coins, amount) {
    const filter = amount + 1;
    const memo = new Array(amount + 1).fill(filter);
    const dp = function(amount) {
        if (amount === 0) {
            return 0;
        }
        if (amount < 0) {
            return -1;
        }
        if (memo[amount] !== filter) {
            return memo[amount];
        }
        for (let coin of coins) {
            let subAmount = dp(amount - coin);
            if (subAmount === -1) {
                continue;
            }
            memo[amount] = Math.min(memo[amount], subAmount + 1);
        }
        return memo[amount] === filter ? -1 : memo[amount]  
    }
    return dp(amount);
}