implement: 322

Author: hijiangtao

README.md

@@ -121,6 +121,7 @@ This is the solutions collection of my LeetCode submissions, most of them are pr
 |309|[Best Time to Buy and Sell Stock with Cooldown](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-cooldown/) | [JavaScript](./src/best-time-to-buy-and-sell-stock-with-cooldown/res.js)|Medium|
 |310|[Minimum Height Trees](https://leetcode.com/problems/minimum-height-trees/) | [JavaScript](./src/minimum-height-trees/res.js)|Medium|
 |315|[Count of Smaller Numbers After Self](https://leetcode.com/problems/count-of-smaller-numbers-after-self/) <sup>*</sup> | [JavaScript](./src/count-of-smaller-numbers-after-self/res.js)|Hard|
+|322|[Coin Change](https://leetcode.com/problems/coin-change/) | [JavaScript](./src/coin-change/res.js)|Medium|
 |327|[Count of Range Sum](https://leetcode.com/problems/count-of-range-sum/) | [JavaScript](./src/count-of-range-sum/res.js)|Hard|
 |334|[Increasing Triplet Subsequence](https://leetcode.com/problems/increasing-triplet-subsequence/) | [JavaScript](./src/increasing-triplet-subsequence/res.js)|Medium|
 |340|[Longest Substring with At Most K Distinct Characters](https://leetcode.com/problems/longest-substring-with-at-most-k-distinct-characters/) | [JavaScript](./src/longest-substring-with-at-most-k-distinct-characters/res.js)|Hard|

src/coin-change/res.js

@@ -0,0 +1,58 @@
+/**
+* @param {number[]} coins
+* @param {number} amount
+* @return {number}
+*/
+var coinChange = function(coins, amount) {
+if (!amount) return 0;
+const mem = [];
+for (let i = 0; i <= amount; i++) {
+mem.push(-2);
+}
+
+const getMaxVal = function(cList, remain) {
+if (remain == 0) return 0;
+if (mem[remain] != -2) return mem[remain];
+let ans = Number.MAX_SAFE_INTEGER;
+
+for (let i = 0; i < cList.length; i++) {
+const ele = cList[i];
+
+if (remain - ele < 0) continue;
+const sub = getMaxVal(cList, remain-ele);
+
+if (sub === -1) continue;
+ans = Math.min(ans, sub+1);
+}
+
+mem[remain] = ans === Number.MAX_SAFE_INTEGER ? -1 : ans;
+return mem[remain];
+}
+
+getMaxVal(coins, amount);
+
+return mem[amount];
+};
+
+/**
+* DP 解法二
+* @param {*} coins
+* @param {*} amount
+*/
+var coinChange = function(coins, amount) {
+if (!amount) return 0;
+const dp = [0];
+
+for (let i = 0; i <= amount; i++) {
+i && dp.push(amount+1);
+for (let j = 0; j < coins.length; j++) {
+const coin = coins[j];
+
+if (coin <= i) {
+dp[i] = Math.min(dp[i], dp[i-coin]+1);
+}
+}
+}
+
+return dp[amount] > amount ? -1 : dp[amount];
+};