add 1415

README.md

@@ -709,4 +709,5 @@ LeetCode
 |1410|[HTML Entity Parser](https://leetcode.com/problems/html-entity-parser/)|c|[c++](./src/1410-HTML-Entity-Parser/1410.cpp)|[python](./src/1410-HTML-Entity-Parser/1410.py)|[go](./src/1410-HTML-Entity-Parser/1410.go)|[js](./src/1410-HTML-Entity-Parser/1410.js)|[java](./src/1410-HTML-Entity-Parser/1410.java)|Medium|
 |1411|[Number of Ways to Paint N×3 Grid](https://leetcode.com/problems/number-of-ways-to-paint-n-3-grid/)|c|[c++](./src/1411-Number-of-Ways-to-Paint-N×3-Grid/1411.cpp)|[python](./src/1411-Number-of-Ways-to-Paint-N×3-Grid/1411.py)|[go](./src/1411-Number-of-Ways-to-Paint-N×3-Grid/1411.go)|[js](./src/1411-Number-of-Ways-to-Paint-N×3-Grid/1411.js)|[java](./src/1411-Number-of-Ways-to-Paint-N×3-Grid/1411.java)|Hard|
 |1413|[Minimum Value to Get Positive Step by Step Sum](https://leetcode.com/problems/minimum-value-to-get-positive-step-by-step-sum/)|c|[c++](./src/1413-Minimum-Value-to-Get-Positive-Step-by-Step-Sum/1413.cpp)|[python](./src/1413-Minimum-Value-to-Get-Positive-Step-by-Step-Sum/1413.py)|[go](./src/1413-Minimum-Value-to-Get-Positive-Step-by-Step-Sum/1413.go)|[js](./src/1413-Minimum-Value-to-Get-Positive-Step-by-Step-Sum/1413.js)|[java](./src/1413-Minimum-Value-to-Get-Positive-Step-by-Step-Sum/1413.java)|Easy|
-|1414|[Find the Minimum Number of Fibonacci Numbers Whose Sum Is K](https://leetcode.com/problems/find-the-minimum-number-of-fibonacci-numbers-whose-sum-is-k/)|c|[c++](./src/1414-Find-the-Minimum-Number-of-Fibonacci-Numbers-Whose-Sum-Is-K/1414.cpp)|[python](./src/1414-Find-the-Minimum-Number-of-Fibonacci-Numbers-Whose-Sum-Is-K/1414.py)|[go](./src/1414-Find-the-Minimum-Number-of-Fibonacci-Numbers-Whose-Sum-Is-K/1414.go)|[js](./src/1414-Find-the-Minimum-Number-of-Fibonacci-Numbers-Whose-Sum-Is-K/1414.js)|[java](./src/1414-Find-the-Minimum-Number-of-Fibonacci-Numbers-Whose-Sum-Is-K/1414.java)|Medium|
+|1414|[Find the Minimum Number of Fibonacci Numbers Whose Sum Is K](https://leetcode.com/problems/find-the-minimum-number-of-fibonacci-numbers-whose-sum-is-k/)|c|[c++](./src/1414-Find-the-Minimum-Number-of-Fibonacci-Numbers-Whose-Sum-Is-K/1414.cpp)|[python](./src/1414-Find-the-Minimum-Number-of-Fibonacci-Numbers-Whose-Sum-Is-K/1414.py)|[go](./src/1414-Find-the-Minimum-Number-of-Fibonacci-Numbers-Whose-Sum-Is-K/1414.go)|[js](./src/1414-Find-the-Minimum-Number-of-Fibonacci-Numbers-Whose-Sum-Is-K/1414.js)|[java](./src/1414-Find-the-Minimum-Number-of-Fibonacci-Numbers-Whose-Sum-Is-K/1414.java)|Medium|
+|1415|[The k-th Lexicographical String of All Happy Strings of Length n](https://leetcode.com/problems/the-k-th-lexicographical-string-of-all-happy-strings-of-length-n/)|c|[c++](./src/1415-The-k-th-Lexicographical-String-of-All-Happy-Strings-of-Length-n/1415.cpp)|[python](./src/1415-The-k-th-Lexicographical-String-of-All-Happy-Strings-of-Length-n/1415.py)|[go](./src/1415-The-k-th-Lexicographical-String-of-All-Happy-Strings-of-Length-n/1415.go)|[js](./src/1415-The-k-th-Lexicographical-String-of-All-Happy-Strings-of-Length-n/1415.js)|[java](./src/1415-The-k-th-Lexicographical-String-of-All-Happy-Strings-of-Length-n/1415.java)|Medium|

src/1415-The-k-th-Lexicographical-String-of-All-Happy-Strings-of-Length-n/1415.cpp

@@ -0,0 +1,16 @@
+class Solution {
+public:
+    string getHappyString(int n, int k) {
+        int prem = 1 << (n - 1);
+        if (k > 3 * prem) return "";
+
+        k--;
+        string s = string(1, 'a' + k / prem);
+        while (prem > 1) {
+            k %= prem;
+            prem >>= 1;
+            s += k / prem == 0 ? 'a' + (s.back() == 'a') : 'b' + (s.back() != 'c');
+        }
+        return s;
+    }
+};

src/1415-The-k-th-Lexicographical-String-of-All-Happy-Strings-of-Length-n/1415.go

@@ -0,0 +1,27 @@
+func getHappyString(n int, k int) string {
+    prem := 1 << (n - 1)
+    if prem * 3 < k {
+        return ""
+    }
+
+    k--
+    s := []byte{byte(97 + k / prem)}
+    for prem > 1 {
+        k %= prem
+        prem >>= 1
+        if k / prem == 0 {
+            if s[len(s) - 1] == 'a' {
+                s = append(s, 'b')
+            } else {
+                s = append(s, 'a')
+            }
+        } else {
+            if s[len(s) - 1] != 'c' {
+                s = append(s, 'c')
+            } else {
+                s = append(s, 'b')
+            }
+        }
+    }
+    return string(s)
+}

src/1415-The-k-th-Lexicographical-String-of-All-Happy-Strings-of-Length-n/1415.java

@@ -0,0 +1,17 @@
+class Solution {
+    public String getHappyString(int n, int k) {
+        int prem = 1 << (n - 1);
+        if (k > 3 * prem) return "";
+
+        k--;
+        StringBuilder s = new StringBuilder();
+        s.append((char)(97 + k / prem));
+        while (prem > 1) {
+            k %= prem;
+            prem >>= 1;
+            s.append(k / prem == 0 ? s.charAt(s.length() - 1) == 'a' ? 'b' : 'a' :
+                                    s.charAt(s.length() - 1) != 'c' ? 'c' : 'b');
+        }
+        return s.toString();
+    }
+}

src/1415-The-k-th-Lexicographical-String-of-All-Happy-Strings-of-Length-n/1415.js

@@ -0,0 +1,14 @@
+var getHappyString = function(n, k) {
+    let prem = 1 << (n - 1);
+    if (k > 3 * prem) return "";
+
+    k--;
+    let s = String.fromCharCode(97 + Math.floor(k / prem));
+    while (prem > 1) {
+        k %= prem;
+        prem >>= 1;
+        s += Math.floor(k / prem) == 0 ? s.charAt(s.length - 1) == 'a' ? 'b' : 'a' :
+                                            s.charAt(s.length - 1) != 'c' ? 'c' : 'b';
+    }
+    return s;
+};

src/1415-The-k-th-Lexicographical-String-of-All-Happy-Strings-of-Length-n/1415.py

@@ -0,0 +1,12 @@
+class Solution:
+    def getHappyString(self, n: int, k: int) -> str:
+        prem = 1 << (n - 1)
+        if prem * 3 < k: return ""
+
+        k -= 1
+        s = chr(97 + k // prem)
+        while prem > 1:
+            k %= prem
+            prem >>= 1
+            s += chr(97 + int(s[-1] == 'a')) if k // prem == 0 else chr(98 + int(s[-1] != 'c'))
+        return s

src/addProb.py

@@ -2,9 +2,9 @@
 import os, bisect
 
 # 题目名称
-name = "Find the Minimum Number of Fibonacci Numbers Whose Sum Is K"
-ID = 1414
-url = "https://leetcode.com/problems/find-the-minimum-number-of-fibonacci-numbers-whose-sum-is-k/"
+name = "The k-th Lexicographical String of All Happy Strings of Length n"
+ID = 1415
+url = "https://leetcode.com/problems/the-k-th-lexicographical-string-of-all-happy-strings-of-length-n/"
 difficult = "Medium"
 prog = ['c', 'cpp', 'py', 'go', 'js', 'java']