update

Author: tangweikun

CATEGORY.md

@@ -57,18 +57,18 @@ https://garciparedes.me/#headers
 
 - Dynamic Programming +7
 
-  - [ ] 357
   - [ ] 376
   - [ ] 1143
   - [ ] 5
   - [ ] 91
   - [ ] 152
-  - [ ] 264
-  - [ ] 279
-  - [ ] 300
-  - [ ] 309
-  - [ ] 322
-  - [ ] 343
+    - [ ] 264
+    - [ ] 279
+    - [ ] 300
+    - [ ] 309
+      - [ ] 322
+        - [ ] 343
+        - [ ] 357
 
 - Greedy
 

src/264-ugly-number-ii/index.js

@@ -1,14 +1,14 @@
 // HELP:
 
-export function nthUglyNumber(num) {
+function nthUglyNumber(num) {
   let dp = [1];
-  let [a, b, c] = [0, 0, 0];
+  let [two, three, five] = [0, 0, 0];
 
   for (let i = 1; i < num; i++) {
-    dp[i] = Math.min(dp[a] * 2, dp[b] * 3, dp[c] * 5);
-    if (dp[i] === dp[a] * 2) a++;
-    if (dp[i] === dp[b] * 3) b++;
-    if (dp[i] === dp[c] * 5) c++;
+    dp[i] = Math.min(dp[two] * 2, dp[three] * 3, dp[five] * 5);
+    if (dp[i] === dp[two] * 2) two++;
+    if (dp[i] === dp[three] * 3) three++;
+    if (dp[i] === dp[five] * 5) five++;
   }
 
   return dp[num - 1];

src/357-count-numbers-with-unique-digits/20210722.js

@@ -0,0 +1,18 @@
+/**
+ * @param {number} n
+ * @return {number}
+ */
+var countNumbersWithUniqueDigits = function (n) {
+  if (n === 0) return 0;
+  if (n === 1) return 10;
+  const dp = [0, 10];
+  for (let i = 2; i <= n; i++) {
+    let sum = Array(i - 1)
+      .fill(0)
+      .reduce((acc, _, index) => acc * Math.max(9 - index, 1), 9);
+
+    dp[i] = dp[i - 1] + sum;
+  }
+
+  return dp[n];
+};

src/91-decode-ways/20210722.js

@@ -0,0 +1,26 @@
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var numDecodings = function (s) {
+  if (s === "0") return 0;
+  let pre1 = 1;
+  let pre2 = 0;
+  let current = 0;
+
+  for (let i = 1; i <= s.length; i++) {
+    current = 0;
+
+    if (s[i - 1] !== "0") {
+      current += pre1;
+    }
+    if (s[i - 2] !== "0" && s[i - 2] * 10 + s[i - 1] * 1 <= 26) {
+      current += pre2;
+    }
+
+    pre2 = pre1;
+    pre1 = current;
+  }
+
+  return current;
+};