feat: add solutions to lc problem: No.1400

No.1400.Construct K Palindrome Strings

Author: yanglbme

.gitignore

@@ -1,6 +1,8 @@
 .idea/
 .DS_Store
 .vscode
+.temp
+.cache
 /node_modules
 /solution/result.json
 /solution/contest.json

solution/1400-1499/1400.Construct K Palindrome Strings/README.md

@@ -67,6 +67,14 @@
 
 <!-- 这里可写通用的实现逻辑 -->
 
+**方法一：计数**
+
+我们先判断字符串 $s$ 的长度是否小于 $k$，如果是，那么一定无法构造出 $k$ 个回文串，可以直接返回 `false`。
+
+否则，我们用一个哈希表或数组 $cnt$ 统计字符串 $s$ 中每个字符出现的次数。最后，我们只需要统计 $cnt$ 中奇数次数的字符个数 $x$，如果 $x$ 大于 $k$，那么一定无法构造出 $k$ 个回文串，返回 `false`；否则，返回 `true`。
+
+时间复杂度 $O(n)$，空间复杂度 $O(C)$。其中 $n$ 是字符串 $s$ 的长度；而 $C$ 是字符集大小，这里 $C=26$。
+
 <!-- tabs:start -->
 
 ### **Python3**
@@ -78,9 +86,8 @@ class Solution:
     def canConstruct(self, s: str, k: int) -> bool:
         if len(s) < k:
             return False
-        counter = Counter(s)
-        cnt = sum(1 for n in counter.values() if n % 2 == 1)
-        return cnt <= k
+        cnt = Counter(s)
+        return sum(v & 1 for v in cnt.values()) <= k
 ```
 
 ### **Java**
@@ -90,20 +97,19 @@ class Solution:
 ```java
 class Solution {
     public boolean canConstruct(String s, int k) {
-        if (s.length() < k) {
+        int n = s.length();
+        if (n < k) {
             return false;
         }
-        int[] counter = new int[26];
-        for (char c : s.toCharArray()) {
-            ++counter[c - 'a'];
+        int[] cnt = new int[26];
+        for (int i = 0; i < n; ++i) {
+            ++cnt[s.charAt(i) - 'a'];
         }
-        int cnt = 0;
-        for (int v : counter) {
-            if (v % 2 == 1) {
-                ++cnt;
-            }
+        int x = 0;
+        for (int v : cnt) {
+            x += v & 1;
         }
-        return cnt <= k;
+        return x <= k;
     }
 }
 ```
@@ -114,14 +120,18 @@ class Solution {
 class Solution {
 public:
     bool canConstruct(string s, int k) {
-        if (s.size() < k) return 0;
-        vector<int> counter(26);
-        for (char c : s) ++counter[c - 'a'];
-        int cnt = 0;
-        for (int v : counter)
-            if (v % 2)
-                ++cnt;
-        return cnt <= k;
+        if (s.size() < k) {
+            return false;
+        }
+        int cnt[26]{};
+        for (char& c : s) {
+            ++cnt[c - 'a'];
+        }
+        int x = 0;
+        for (int v : cnt) {
+            x += v & 1;
+        }
+        return x <= k;
     }
 };
 ```
@@ -133,17 +143,34 @@ func canConstruct(s string, k int) bool {
 	if len(s) < k {
 		return false
 	}
-	counter := make([]int, 26)
+	cnt := [26]int{}
 	for _, c := range s {
-		counter[c-'a']++
+		cnt[c-'a']++
 	}
-	cnt := 0
-	for _, v := range counter {
-		if v%2 == 1 {
-			cnt++
-		}
+	x := 0
+	for _, v := range cnt {
+		x += v & 1
 	}
-	return cnt <= k
+	return x <= k
+}
+```
+
+### **TypeScript**
+
+```ts
+function canConstruct(s: string, k: number): boolean {
+    if (s.length < k) {
+        return false;
+    }
+    const cnt: number[] = new Array(26).fill(0);
+    for (const c of s) {
+        ++cnt[c.charCodeAt(0) - 'a'.charCodeAt(0)];
+    }
+    let x = 0;
+    for (const v of cnt) {
+        x += v & 1;
+    }
+    return x <= k;
 }
 ```
 

solution/1400-1499/1400.Construct K Palindrome Strings/README_EN.md

@@ -52,30 +52,28 @@ class Solution:
     def canConstruct(self, s: str, k: int) -> bool:
         if len(s) < k:
             return False
-        counter = Counter(s)
-        cnt = sum(1 for n in counter.values() if n % 2 == 1)
-        return cnt <= k
+        cnt = Counter(s)
+        return sum(v & 1 for v in cnt.values()) <= k
 ```
 
 ### **Java**
 
 ```java
 class Solution {
     public boolean canConstruct(String s, int k) {
-        if (s.length() < k) {
+        int n = s.length();
+        if (n < k) {
             return false;
         }
-        int[] counter = new int[26];
-        for (char c : s.toCharArray()) {
-            ++counter[c - 'a'];
+        int[] cnt = new int[26];
+        for (int i = 0; i < n; ++i) {
+            ++cnt[s.charAt(i) - 'a'];
         }
-        int cnt = 0;
-        for (int v : counter) {
-            if (v % 2 == 1) {
-                ++cnt;
-            }
+        int x = 0;
+        for (int v : cnt) {
+            x += v & 1;
         }
-        return cnt <= k;
+        return x <= k;
     }
 }
 ```
@@ -86,14 +84,18 @@ class Solution {
 class Solution {
 public:
     bool canConstruct(string s, int k) {
-        if (s.size() < k) return 0;
-        vector<int> counter(26);
-        for (char c : s) ++counter[c - 'a'];
-        int cnt = 0;
-        for (int v : counter)
-            if (v % 2)
-                ++cnt;
-        return cnt <= k;
+        if (s.size() < k) {
+            return false;
+        }
+        int cnt[26]{};
+        for (char& c : s) {
+            ++cnt[c - 'a'];
+        }
+        int x = 0;
+        for (int v : cnt) {
+            x += v & 1;
+        }
+        return x <= k;
     }
 };
 ```
@@ -105,17 +107,34 @@ func canConstruct(s string, k int) bool {
 	if len(s) < k {
 		return false
 	}
-	counter := make([]int, 26)
+	cnt := [26]int{}
 	for _, c := range s {
-		counter[c-'a']++
+		cnt[c-'a']++
 	}
-	cnt := 0
-	for _, v := range counter {
-		if v%2 == 1 {
-			cnt++
-		}
+	x := 0
+	for _, v := range cnt {
+		x += v & 1
 	}
-	return cnt <= k
+	return x <= k
+}
+```
+
+### **TypeScript**
+
+```ts
+function canConstruct(s: string, k: number): boolean {
+    if (s.length < k) {
+        return false;
+    }
+    const cnt: number[] = new Array(26).fill(0);
+    for (const c of s) {
+        ++cnt[c.charCodeAt(0) - 'a'.charCodeAt(0)];
+    }
+    let x = 0;
+    for (const v of cnt) {
+        x += v & 1;
+    }
+    return x <= k;
 }
 ```
 

solution/1400-1499/1400.Construct K Palindrome Strings/Solution.cpp

@@ -1,13 +1,17 @@
 class Solution {
 public:
     bool canConstruct(string s, int k) {
-        if (s.size() < k) return 0;
-        vector<int> counter(26);
-        for (char c : s) ++counter[c - 'a'];
-        int cnt = 0;
-        for (int v : counter)
-            if (v % 2)
-                ++cnt;
-        return cnt <= k;
+        if (s.size() < k) {
+            return false;
+        }
+        int cnt[26]{};
+        for (char& c : s) {
+            ++cnt[c - 'a'];
+        }
+        int x = 0;
+        for (int v : cnt) {
+            x += v & 1;
+        }
+        return x <= k;
     }
 };

solution/1400-1499/1400.Construct K Palindrome Strings/Solution.go

@@ -2,15 +2,13 @@ func canConstruct(s string, k int) bool {
 	if len(s) < k {
 		return false
 	}
-	counter := make([]int, 26)
+	cnt := [26]int{}
 	for _, c := range s {
-		counter[c-'a']++
+		cnt[c-'a']++
 	}
-	cnt := 0
-	for _, v := range counter {
-		if v%2 == 1 {
-			cnt++
-		}
+	x := 0
+	for _, v := range cnt {
+		x += v & 1
 	}
-	return cnt <= k
+	return x <= k
 }

solution/1400-1499/1400.Construct K Palindrome Strings/Solution.java

@@ -1,18 +1,17 @@
 class Solution {
     public boolean canConstruct(String s, int k) {
-        if (s.length() < k) {
+        int n = s.length();
+        if (n < k) {
             return false;
         }
-        int[] counter = new int[26];
-        for (char c : s.toCharArray()) {
-            ++counter[c - 'a'];
+        int[] cnt = new int[26];
+        for (int i = 0; i < n; ++i) {
+            ++cnt[s.charAt(i) - 'a'];
         }
-        int cnt = 0;
-        for (int v : counter) {
-            if (v % 2 == 1) {
-                ++cnt;
-            }
+        int x = 0;
+        for (int v : cnt) {
+            x += v & 1;
         }
-        return cnt <= k;
+        return x <= k;
     }
 }

solution/1400-1499/1400.Construct K Palindrome Strings/Solution.py

@@ -2,6 +2,5 @@ class Solution:
     def canConstruct(self, s: str, k: int) -> bool:
         if len(s) < k:
             return False
-        counter = Counter(s)
-        cnt = sum(1 for n in counter.values() if n % 2 == 1)
-        return cnt <= k
+        cnt = Counter(s)
+        return sum(v & 1 for v in cnt.values()) <= k

solution/1400-1499/1400.Construct K Palindrome Strings/Solution.ts

@@ -0,0 +1,14 @@
+function canConstruct(s: string, k: number): boolean {
+    if (s.length < k) {
+        return false;
+    }
+    const cnt: number[] = new Array(26).fill(0);
+    for (const c of s) {
+        ++cnt[c.charCodeAt(0) - 'a'.charCodeAt(0)];
+    }
+    let x = 0;
+    for (const v of cnt) {
+        x += v & 1;
+    }
+    return x <= k;
+}

solution/2600-2699/2647.Color the Triangle Red/README.md

@@ -22,14 +22,12 @@
 
 <ol>
 	<li>选择一个 <strong>至少有两个</strong> 红色相邻三角形的白色三角形。
-
     <ul>
     	<li>如果没有这样的三角形，请停止算法。</li>
     </ul>
     </li>
     <li>将该三角形涂成 <strong>红色</strong> 。</li>
     <li>回到步骤 1。</li>
-
 </ol>
 
 <p>选择最小的 <code>k</code> 并在运行此算法之前将 <code>k</code> 个三角形涂成红色，使得在算法停止后，所有单元三角形都被涂成红色。</p>

solution/2600-2699/2677.Chunk Array/README.md

@@ -73,4 +73,21 @@ function chunk(arr: any[], size: number): any[][] {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {Array} arr
+ * @param {number} size
+ * @return {Array[]}
+ */
+var chunk = function (arr, size) {
+    const ans = [];
+    for (let i = 0, n = arr.length; i < n; i += size) {
+        ans.push(arr.slice(i, i + size));
+    }
+    return ans;
+};
+```
+
 <!-- tabs:end -->