[jdy8739] Week 1

climbing-stairs/jdy8739.js

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+/**
+ * @param {number} n
+ * @return {number}
+ */
+var climbStairs = function(n) {
+    let first = 1;
+    let second = 2;
+
+    if (n <= 2) {
+        return n;
+    }
+
+    for (let i=2; i<n; i++) {
+        let tmp = second;
+        second = first + second;
+        first = tmp;
+    }
+
+    return second;
+};
+
+

coin-change/jdy8739.js

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+/**
+ * @param {number[]} coins
+ * @param {number} amount
+ * @return {number}
+ */
+var coinChange = function(coins, amount) {
+    const dp = [0, ...(new Array(amount).fill(amount + 1))];
+
+    for (coin of coins) {
+        for (let a = coin; a <= amount; a++) {
+            dp[a] = Math.min(dp[a], dp[a - coin] + 1);
+        }
+    }
+
+    return dp[amount] < amount + 1 ? dp[amount] : -1
+};
+