力扣hot100 零钱兑换 背包 滚动数组

Problem: 322. 零钱兑换

思路

‍ 大佬题解

Code

⏰ 时间复杂度: $O(n)$

class Solution {
	public int coinChange(int[] coins, int amount)
	{
        int INF = 0x3f3f3f3f;
		int n = amount;
		int[] f = new int[n + 1];
        Arrays.fill(f, INF);
        f[0] = 0;
		for (int i = 0; i < coins.length; i++)
		{
			int x = coins[i];
			for (int j = x; j <= n; j++)
				f[j] = Math.min(f[j], f[j - x] + 1);
		}
        if(f[n] == INF)
            return -1;
		return f[n];
	}
}