feat: update solutions to lc problem: No.2399

No.2399.Check Distances Between Same Letters

Author: yanglbme

solution/2300-2399/2399.Check Distances Between Same Letters/README.md

@@ -55,9 +55,9 @@
 
 **方法一：数组或哈希表**
 
-我们可以用哈希表 $d$ 记录每个字母出现的下标，然后遍历哈希表，判断每个字母的下标之差是否等于 `distance` 中对应的值。
+我们可以用哈希表 $d$ 记录每个字母出现的下标，然后遍历哈希表，判断每个字母的下标之差是否等于 `distance` 中对应的值。如果出现不等的情况，直接返回 `false`。如果遍历结束后，没有出现不等的情况，返回 `true`。
 
-时间复杂度 $O(n)$，其中 $n$ 为字符串 $s$ 的长度。
+时间复杂度 $O(n)$，空间复杂度 $O(C)$。其中 $n$ 为字符串 $s$ 的长度，而 $C$ 为字符集大小，本题中 $C = 26$。
 
 <!-- tabs:start -->
 
@@ -68,12 +68,11 @@
 ```python
 class Solution:
     def checkDistances(self, s: str, distance: List[int]) -> bool:
-        d = [0] * 26
-        for i, c in enumerate(s):
-            j = ord(c) - ord("a")
-            if d[j] and i - d[j] != distance[j]:
+        d = defaultdict(int)
+        for i, c in enumerate(s, 1):
+            if d[c] and i - d[c] - 1 != distance[ord(c) - ord('a')]:
                 return False
-            d[j] = i + 1
+            d[c] = i
         return True
 ```
 
@@ -85,12 +84,12 @@ class Solution:
 class Solution {
     public boolean checkDistances(String s, int[] distance) {
         int[] d = new int[26];
-        for (int i = 0; i < s.length(); ++i) {
-            int j = s.charAt(i) - 'a';
-            if (d[j] > 0 && i - d[j] != distance[j]) {
+        for (int i = 1, n = s.length(); i <= n; ++i) {
+            int j = s.charAt(i - 1) - 'a';
+            if (d[j] > 0 && i - d[j] - 1 != distance[j]) {
                 return false;
             }
-            d[j] = i + 1;
+            d[j] = i;
         }
         return true;
     }
@@ -103,13 +102,13 @@ class Solution {
 class Solution {
 public:
     bool checkDistances(string s, vector<int>& distance) {
-        vector<int> d(26);
-        for (int i = 0; i < s.size(); ++i) {
-            int j = s[i] - 'a';
-            if (d[j] && i - d[j] != distance[j]) {
+        int d[26]{};
+        for (int i = 1; i <= s.size(); ++i) {
+            int j = s[i - 1] - 'a';
+            if (d[j] && i - d[j] - 1 != distance[j]) {
                 return false;
             }
-            d[j] = i + 1;
+            d[j] = i;
         }
         return true;
     }
@@ -120,13 +119,13 @@ public:
 
 ```go
 func checkDistances(s string, distance []int) bool {
-	d := make([]int, 26)
+	d := [26]int{}
 	for i, c := range s {
-		j := c - 'a'
-		if d[j] > 0 && i-d[j] != distance[j] {
+		c -= 'a'
+		if d[c] > 0 && i-d[c] != distance[c] {
 			return false
 		}
-		d[j] = i + 1
+		d[c] = i + 1
 	}
 	return true
 }
@@ -154,13 +153,13 @@ bool checkDistances(char *s, int *distance, int distanceSize) {
 ```ts
 function checkDistances(s: string, distance: number[]): boolean {
     const n = s.length;
-    const d = new Array(26).fill(0);
-    for (let i = 0; i < n; i++) {
-        const j = s[i].charCodeAt(0) - 'a'.charCodeAt(0);
-        if (d[j] > 0 && i - d[j] !== distance[j]) {
+    const d: number[] = new Array(26).fill(0);
+    for (let i = 1; i <= n; ++i) {
+        const j = s.charCodeAt(i - 1) - 97;
+        if (d[j] && i - d[j] - 1 != distance[j]) {
             return false;
         }
-        d[j] = i + 1;
+        d[j] = i;
     }
     return true;
 }

solution/2300-2399/2399.Check Distances Between Same Letters/README_EN.md

@@ -56,12 +56,11 @@ Because distance[0] = 1, s is not a well-spaced string.
 ```python
 class Solution:
     def checkDistances(self, s: str, distance: List[int]) -> bool:
-        d = [0] * 26
-        for i, c in enumerate(s):
-            j = ord(c) - ord("a")
-            if d[j] and i - d[j] != distance[j]:
+        d = defaultdict(int)
+        for i, c in enumerate(s, 1):
+            if d[c] and i - d[c] - 1 != distance[ord(c) - ord('a')]:
                 return False
-            d[j] = i + 1
+            d[c] = i
         return True
 ```
 
@@ -71,12 +70,12 @@ class Solution:
 class Solution {
     public boolean checkDistances(String s, int[] distance) {
         int[] d = new int[26];
-        for (int i = 0; i < s.length(); ++i) {
-            int j = s.charAt(i) - 'a';
-            if (d[j] > 0 && i - d[j] != distance[j]) {
+        for (int i = 1, n = s.length(); i <= n; ++i) {
+            int j = s.charAt(i - 1) - 'a';
+            if (d[j] > 0 && i - d[j] - 1 != distance[j]) {
                 return false;
             }
-            d[j] = i + 1;
+            d[j] = i;
         }
         return true;
     }
@@ -89,13 +88,13 @@ class Solution {
 class Solution {
 public:
     bool checkDistances(string s, vector<int>& distance) {
-        vector<int> d(26);
-        for (int i = 0; i < s.size(); ++i) {
-            int j = s[i] - 'a';
-            if (d[j] && i - d[j] != distance[j]) {
+        int d[26]{};
+        for (int i = 1; i <= s.size(); ++i) {
+            int j = s[i - 1] - 'a';
+            if (d[j] && i - d[j] - 1 != distance[j]) {
                 return false;
             }
-            d[j] = i + 1;
+            d[j] = i;
         }
         return true;
     }
@@ -106,13 +105,13 @@ public:
 
 ```go
 func checkDistances(s string, distance []int) bool {
-	d := make([]int, 26)
+	d := [26]int{}
 	for i, c := range s {
-		j := c - 'a'
-		if d[j] > 0 && i-d[j] != distance[j] {
+		c -= 'a'
+		if d[c] > 0 && i-d[c] != distance[c] {
 			return false
 		}
-		d[j] = i + 1
+		d[c] = i + 1
 	}
 	return true
 }
@@ -140,13 +139,13 @@ bool checkDistances(char *s, int *distance, int distanceSize) {
 ```ts
 function checkDistances(s: string, distance: number[]): boolean {
     const n = s.length;
-    const d = new Array(26).fill(0);
-    for (let i = 0; i < n; i++) {
-        const j = s[i].charCodeAt(0) - 'a'.charCodeAt(0);
-        if (d[j] > 0 && i - d[j] !== distance[j]) {
+    const d: number[] = new Array(26).fill(0);
+    for (let i = 1; i <= n; ++i) {
+        const j = s.charCodeAt(i - 1) - 97;
+        if (d[j] && i - d[j] - 1 != distance[j]) {
             return false;
         }
-        d[j] = i + 1;
+        d[j] = i;
     }
     return true;
 }

solution/2300-2399/2399.Check Distances Between Same Letters/Solution.cpp

@@ -1,13 +1,13 @@
 class Solution {
 public:
     bool checkDistances(string s, vector<int>& distance) {
-        vector<int> d(26);
-        for (int i = 0; i < s.size(); ++i) {
-            int j = s[i] - 'a';
-            if (d[j] && i - d[j] != distance[j]) {
+        int d[26]{};
+        for (int i = 1; i <= s.size(); ++i) {
+            int j = s[i - 1] - 'a';
+            if (d[j] && i - d[j] - 1 != distance[j]) {
                 return false;
             }
-            d[j] = i + 1;
+            d[j] = i;
         }
         return true;
     }

solution/2300-2399/2399.Check Distances Between Same Letters/Solution.go

@@ -1,11 +1,11 @@
 func checkDistances(s string, distance []int) bool {
-	d := make([]int, 26)
+	d := [26]int{}
 	for i, c := range s {
-		j := c - 'a'
-		if d[j] > 0 && i-d[j] != distance[j] {
+		c -= 'a'
+		if d[c] > 0 && i-d[c] != distance[c] {
 			return false
 		}
-		d[j] = i + 1
+		d[c] = i + 1
 	}
 	return true
 }

solution/2300-2399/2399.Check Distances Between Same Letters/Solution.java

@@ -1,12 +1,12 @@
 class Solution {
     public boolean checkDistances(String s, int[] distance) {
         int[] d = new int[26];
-        for (int i = 0; i < s.length(); ++i) {
-            int j = s.charAt(i) - 'a';
-            if (d[j] > 0 && i - d[j] != distance[j]) {
+        for (int i = 1, n = s.length(); i <= n; ++i) {
+            int j = s.charAt(i - 1) - 'a';
+            if (d[j] > 0 && i - d[j] - 1 != distance[j]) {
                 return false;
             }
-            d[j] = i + 1;
+            d[j] = i;
         }
         return true;
     }

solution/2300-2399/2399.Check Distances Between Same Letters/Solution.py

@@ -1,9 +1,8 @@
 class Solution:
     def checkDistances(self, s: str, distance: List[int]) -> bool:
-        d = [0] * 26
-        for i, c in enumerate(s):
-            j = ord(c) - ord("a")
-            if d[j] and i - d[j] != distance[j]:
+        d = defaultdict(int)
+        for i, c in enumerate(s, 1):
+            if d[c] and i - d[c] - 1 != distance[ord(c) - ord('a')]:
                 return False
-            d[j] = i + 1
+            d[c] = i
         return True

solution/2300-2399/2399.Check Distances Between Same Letters/Solution.ts

@@ -1,12 +1,12 @@
 function checkDistances(s: string, distance: number[]): boolean {
     const n = s.length;
-    const d = new Array(26).fill(0);
-    for (let i = 0; i < n; i++) {
-        const j = s[i].charCodeAt(0) - 'a'.charCodeAt(0);
-        if (d[j] > 0 && i - d[j] !== distance[j]) {
+    const d: number[] = new Array(26).fill(0);
+    for (let i = 1; i <= n; ++i) {
+        const j = s.charCodeAt(i - 1) - 97;
+        if (d[j] && i - d[j] - 1 != distance[j]) {
             return false;
         }
-        d[j] = i + 1;
+        d[j] = i;
     }
     return true;
 }