38 count-and-say

malipramod · malipramod · commit 7f1a9278c209 · 2019-09-03T11:40:54.000+05:30
diff --git a/easy/0038 count-and-say/count-and-say.js b/easy/0038 count-and-say/count-and-say.js
@@ -0,0 +1,31 @@
+/**
+ * @param {number} n
+ * @return {string}
+ */
+var countAndSay = function (n) {
+    if (n == 1) return "1";
+    if (n == 2) return "11";
+
+    let res = "11";
+    for (let i = 3; i <= n; i++) {
+        res += '$';
+        let len = res.length;
+        let counter = 1;
+        let tempStr = "";
+        let arr = res.split('');
+
+        for (let j = 1; j < len; j++) {
+            if (arr[j] !== arr[j - 1]) {
+                tempStr += counter + 0;
+                tempStr += arr[j - 1];
+                counter = 1;
+
+            } else
+                counter++;
+        }
+        res = tempStr;
+    }
+    return res;
+};
+
+console.log(countAndSay(10))
diff --git a/easy/0038 count-and-say/readme.md b/easy/0038 count-and-say/readme.md
@@ -0,0 +1,39 @@
+# Count and Say
+
+The count-and-say sequence is the sequence of integers with the first five terms as following:
+
+1 ====> "1"
+
+2 ====> "11"
+
+3 ====> "21"
+
+4 ====> "1211"
+
+5 ====> "111221"
+
+1 is read off as "one 1" or 11.
+
+11 is read off as "two 1s" or 21.
+
+21 is read off as "one 2, then one 1" or 1211.
+
+Given an integer n where 1 ≤ n ≤ 30, generate the nth term of the count-and-say sequence.
+
+Note: Each term of the sequence of integers will be represented as a string.
+
+## Example 1
+
+Input: 1
+
+Output: "1"
+
+## Example 2
+
+Input: 4
+
+Output: "1211"
+
+## More Info
+
+<https://leetcode.com/problems/count-and-say/>
diff --git a/medium/0036 valid-sudoku/readme.md b/medium/0036 valid-sudoku/readme.md
@@ -0,0 +1,58 @@
+# Valid Sudoku
+
+Determine if a 9x9 Sudoku board is valid. Only the filled cells need to be validated according to the following rules:
+
+Each row must contain the digits 1-9 without repetition.
+
+Each column must contain the digits 1-9 without repetition.
+
+Each of the 9 3x3 sub-boxes of the grid must contain the digits 1-9 without repetition.
+
+The Sudoku board could be partially filled, where empty cells are filled with the character '.'.
+
+## Example 1
+
+Input:
+
+[
+
+  ["5","3",".",".","7",".",".",".","."],
+
+  ["6",".",".","1","9","5",".",".","."],
+
+  [".","9","8",".",".",".",".","6","."],
+
+  ["8",".",".",".","6",".",".",".","3"],
+
+  ["4",".",".","8",".","3",".",".","1"],
+
+  ["7",".",".",".","2",".",".",".","6"],
+
+  [".","6",".",".",".",".","2","8","."],
+
+  [".",".",".","4","1","9",".",".","5"],
+
+  [".",".",".",".","8",".",".","7","9"]
+
+]
+
+Output: true
+
+## Example 2
+
+Input:
+[
+  ["8","3",".",".","7",".",".",".","."],
+  ["6",".",".","1","9","5",".",".","."],
+  [".","9","8",".",".",".",".","6","."],
+  ["8",".",".",".","6",".",".",".","3"],
+  ["4",".",".","8",".","3",".",".","1"],
+  ["7",".",".",".","2",".",".",".","6"],
+  [".","6",".",".",".",".","2","8","."],
+  [".",".",".","4","1","9",".",".","5"],
+  [".",".",".",".","8",".",".","7","9"]
+]
+
+Output: false
+
+Explanation: Same as Example 1, except with the 5 in the top left corner being modified to 8. Since there are two 8's in the top left 3x3 sub-box, it is invalid.
diff --git a/medium/0036 valid-sudoku/valid-sudoku.js b/medium/0036 valid-sudoku/valid-sudoku.js
