Day79

swolecoder · swolecoder · commit ceecd4596788 · 2020-12-26T12:18:35.000-05:00
diff --git a/Day79/index.js b/Day79/index.js
@@ -0,0 +1,27 @@
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var numDecodings = function (s) {
+
+
+
+    let dp = new Array(s.length + 1).fill(0);
+
+    dp[0] = 1; //empty steriung
+
+    dp[1] = s.charAt(0) == 0 ? 0 : 1;
+
+    for (let i = 2; i <= s.length; i++) {
+        let oneDigit = +s.slice(i - 1, i);
+        let twoDigit = +s.slice(i - 2, i);
+        if (oneDigit >= 1) {
+            dp[i] += dp[i - 1]
+        }
+        if (twoDigit >= 10 && twoDigit <= 26) {
+            dp[i] += dp[i - 2]
+        }
+    }
+
+    return dp[s.length]
+};
diff --git a/README.md b/README.md
@@ -176,4 +176,6 @@ If you are loving solving problems in leetcode, please contact me to enjoy it to
 
 |Day 77| [24. Swap Nodes in Pairs](https://leetcode.com/problems/swap-nodes-in-pairs/) | [javascript]()|[:memo:](https://leetcode.com/problems/swap-nodes-in-pairs/)|Medium|
 
-|Day 78| [498. Diagonal Traverse](https://leetcode.com/problems/diagonal-traverse/) | [javascript]()|[:memo:](https://leetcode.com/problems/diagonal-traverse/)|Medium|
+|Day 78| [498. Diagonal Traverse](https://leetcode.com/problems/diagonal-traverse/) | [javascript]()|[:memo:](https://leetcode.com/problems/diagonal-traverse/)|Medium|
+
+|Day 79| [91. Decode Ways](https://leetcode.com/problems/decode-ways/) | [javascript]()|[:memo:](https://leetcode.com/problems/decode-ways/)|Medium|
