LeetCode 322: Coin Change (硬币找零, DP经典题)

  1. Coin Change
    Medium
    17.4K
    391
    Companies
    You are given an integer array coins representing coins of different denominations and an integer amount representing a total amount of money.

Return the fewest number of coins that you need to make up that amount. If that amount of money cannot be made up by any combination of the coins, return -1.

You may assume that you have an infinite number of each kind of coin.

Example 1:

Input: coins = [1,2,5], amount = 11

Output: 3

Explanation: 11 = 5 + 5 + 1

Example 2:

Input: coins = [2], amount = 3

Output: -1

Example 3:

Input: coins = [1], amount = 0

Output: 0

Constraints:

1 <= coins.length <= 12

1 <= coins[i] <= 231 - 1

0 <= amount <= 104

解法1:动态规划。注意此题不可用贪婪法。比如coins = {1, 3, 4}, amount = 6. 用贪婪法得到{4, 1, 1}这种组合,但实际上最优解是{3,3}。

cpp 复制代码
class Solution {
public:
    int coinChange(vector<int>& coins, int amount) {
        int n = coins.size();
        if (n == 0 || amount == 0) return 0;
        vector<int> dp(amount + 1, INT_MAX);
        for (int i = 1; i <= amount; i++) {
            for (auto j : coins) {
                if (i == j) dp[i] = 1;
                else if (i > j && dp[i - j] != INT_MAX) {
                    dp[i] = min(dp[i], dp[i - j] + 1);
                }
            }
        }
        if (dp[amount] == INT_MAX) return -1;
        return dp[amount];
    }
};
相关推荐
茉莉玫瑰花茶1 天前
算法 --- 字符串
算法
博笙困了1 天前
AcWing学习——差分
c++·算法
NAGNIP1 天前
认识 Unsloth 框架:大模型高效微调的利器
算法
NAGNIP1 天前
大模型微调框架之LLaMA Factory
算法
echoarts1 天前
Rayon Rust中的数据并行库入门教程
开发语言·其他·算法·rust
Python技术极客1 天前
一款超好用的 Python 交互式可视化工具,强烈推荐~
算法
徐小夕1 天前
花了一天时间,开源了一套精美且支持复杂操作的表格编辑器tablejs
前端·算法·github
小刘鸭地下城1 天前
深入浅出链表:从基础概念到核心操作全面解析
算法
小刘鸭地下城1 天前
哈希表核心精要:从 O(1) 原理到链式地址与开放寻址
算法
BenChuat1 天前
Java常见排序算法实现
java·算法·排序算法