feat: update solutions to lc problem: No.0942 (doocs#3210)

No.0942.DI String Match

Author: yanglbme

solution/0900-0999/0942.DI String Match/README.md

@@ -65,7 +65,13 @@ tags:
 
 <!-- solution:start -->
 
-### 方法一
+### 方法一：贪心
+
+我们可以使用两个指针 `low` 和 `high` 分别表示当前的最小值和最大值，然后遍历字符串 `s`，如果当前字符是 `I`，那么我们就将 `low` 加入到结果数组中，并且 `low` 自增 1；如果当前字符是 `D`，那么我们就将 `high` 加入到结果数组中，并且 `high` 自减 1。
+
+最后，我们将 `low` 加入到结果数组中，返回结果数组即可。
+
+时间复杂度 $O(n)$，空间复杂度 $O(n)$。其中 $n$ 为字符串 `s` 的长度。
 
 <!-- tabs:start -->
 
@@ -74,11 +80,10 @@ tags:
 ```python
 class Solution:
     def diStringMatch(self, s: str) -> List[int]:
-        n = len(s)
-        low, high = 0, n
+        low, high = 0, len(s)
         ans = []
-        for i in range(n):
-            if s[i] == 'I':
+        for c in s:
+            if c == "I":
                 ans.append(low)
                 low += 1
             else:
@@ -134,12 +139,10 @@ public:
 #### Go
 
 ```go
-func diStringMatch(s string) []int {
-	n := len(s)
-	low, high := 0, n
-	var ans []int
-	for i := 0; i < n; i++ {
-		if s[i] == 'I' {
+func diStringMatch(s string) (ans []int) {
+	low, high := 0, len(s)
+	for _, c := range s {
+		if c == 'I' {
 			ans = append(ans, low)
 			low++
 		} else {
@@ -148,27 +151,25 @@ func diStringMatch(s string) []int {
 		}
 	}
 	ans = append(ans, low)
-	return ans
+	return
 }
 ```
 
 #### TypeScript
 
 ```ts
 function diStringMatch(s: string): number[] {
-    const n = s.length;
-    const res = new Array(n + 1);
-    let low = 0;
-    let high = n;
-    for (let i = 0; i < n; i++) {
-        if (s[i] === 'I') {
-            res[i] = low++;
+    const ans: number[] = [];
+    let [low, high] = [0, s.length];
+    for (const c of s) {
+        if (c === 'I') {
+            ans.push(low++);
         } else {
-            res[i] = high--;
+            ans.push(high--);
         }
     }
-    res[n] = low;
-    return res;
+    ans.push(low);
+    return ans;
 }
 ```
 
@@ -177,21 +178,22 @@ function diStringMatch(s: string): number[] {
 ```rust
 impl Solution {
     pub fn di_string_match(s: String) -> Vec<i32> {
-        let s = s.as_bytes();
-        let n = s.len();
-        let mut res = Vec::with_capacity(n + 1);
-        let (mut low, mut high) = (-1, (n + 1) as i32);
-        for i in 0..n {
-            res.push(if s[i] == b'I' {
+        let mut low = 0;
+        let mut high = s.len() as i32;
+        let mut ans = Vec::with_capacity(s.len() + 1);
+
+        for c in s.chars() {
+            if c == 'I' {
+                ans.push(low);
                 low += 1;
-                low
             } else {
+                ans.push(high);
                 high -= 1;
-                high
-            });
+            }
         }
-        res.push(low + 1);
-        res
+
+        ans.push(low);
+        ans
     }
 }
 ```

solution/0900-0999/0942.DI String Match/README_EN.md

@@ -53,7 +53,13 @@ tags:
 
 <!-- solution:start -->
 
-### Solution 1
+### Solution 1: Greedy Algorithm
+
+We can use two pointers `low` and `high` to represent the current minimum and maximum values, respectively. Then, we traverse the string `s`. If the current character is `I`, we add `low` to the result array, and increment `low` by 1; if the current character is `D`, we add `high` to the result array, and decrement `high` by 1.
+
+Finally, we add `low` to the result array and return the result array.
+
+The time complexity is $O(n)$, and the space complexity is $O(n)$, where $n$ is the length of the string `s`.
 
 <!-- tabs:start -->
 
@@ -62,11 +68,10 @@ tags:
 ```python
 class Solution:
     def diStringMatch(self, s: str) -> List[int]:
-        n = len(s)
-        low, high = 0, n
+        low, high = 0, len(s)
         ans = []
-        for i in range(n):
-            if s[i] == 'I':
+        for c in s:
+            if c == "I":
                 ans.append(low)
                 low += 1
             else:
@@ -122,12 +127,10 @@ public:
 #### Go
 
 ```go
-func diStringMatch(s string) []int {
-	n := len(s)
-	low, high := 0, n
-	var ans []int
-	for i := 0; i < n; i++ {
-		if s[i] == 'I' {
+func diStringMatch(s string) (ans []int) {
+	low, high := 0, len(s)
+	for _, c := range s {
+		if c == 'I' {
 			ans = append(ans, low)
 			low++
 		} else {
@@ -136,27 +139,25 @@ func diStringMatch(s string) []int {
 		}
 	}
 	ans = append(ans, low)
-	return ans
+	return
 }
 ```
 
 #### TypeScript
 
 ```ts
 function diStringMatch(s: string): number[] {
-    const n = s.length;
-    const res = new Array(n + 1);
-    let low = 0;
-    let high = n;
-    for (let i = 0; i < n; i++) {
-        if (s[i] === 'I') {
-            res[i] = low++;
+    const ans: number[] = [];
+    let [low, high] = [0, s.length];
+    for (const c of s) {
+        if (c === 'I') {
+            ans.push(low++);
         } else {
-            res[i] = high--;
+            ans.push(high--);
         }
     }
-    res[n] = low;
-    return res;
+    ans.push(low);
+    return ans;
 }
 ```
 
@@ -165,21 +166,22 @@ function diStringMatch(s: string): number[] {
 ```rust
 impl Solution {
     pub fn di_string_match(s: String) -> Vec<i32> {
-        let s = s.as_bytes();
-        let n = s.len();
-        let mut res = Vec::with_capacity(n + 1);
-        let (mut low, mut high) = (-1, (n + 1) as i32);
-        for i in 0..n {
-            res.push(if s[i] == b'I' {
+        let mut low = 0;
+        let mut high = s.len() as i32;
+        let mut ans = Vec::with_capacity(s.len() + 1);
+
+        for c in s.chars() {
+            if c == 'I' {
+                ans.push(low);
                 low += 1;
-                low
             } else {
+                ans.push(high);
                 high -= 1;
-                high
-            });
+            }
         }
-        res.push(low + 1);
-        res
+
+        ans.push(low);
+        ans
     }
 }
 ```

solution/0900-0999/0942.DI String Match/Solution.go

@@ -1,9 +1,7 @@
-func diStringMatch(s string) []int {
-	n := len(s)
-	low, high := 0, n
-	var ans []int
-	for i := 0; i < n; i++ {
-		if s[i] == 'I' {
+func diStringMatch(s string) (ans []int) {
+	low, high := 0, len(s)
+	for _, c := range s {
+		if c == 'I' {
 			ans = append(ans, low)
 			low++
 		} else {
@@ -12,5 +10,5 @@ func diStringMatch(s string) []int {
 		}
 	}
 	ans = append(ans, low)
-	return ans
+	return
 }

solution/0900-0999/0942.DI String Match/Solution.py

@@ -1,10 +1,9 @@
 class Solution:
     def diStringMatch(self, s: str) -> List[int]:
-        n = len(s)
-        low, high = 0, n
+        low, high = 0, len(s)
         ans = []
-        for i in range(n):
-            if s[i] == 'I':
+        for c in s:
+            if c == "I":
                 ans.append(low)
                 low += 1
             else:

solution/0900-0999/0942.DI String Match/Solution.rs

@@ -1,19 +1,20 @@
 impl Solution {
     pub fn di_string_match(s: String) -> Vec<i32> {
-        let s = s.as_bytes();
-        let n = s.len();
-        let mut res = Vec::with_capacity(n + 1);
-        let (mut low, mut high) = (-1, (n + 1) as i32);
-        for i in 0..n {
-            res.push(if s[i] == b'I' {
+        let mut low = 0;
+        let mut high = s.len() as i32;
+        let mut ans = Vec::with_capacity(s.len() + 1);
+
+        for c in s.chars() {
+            if c == 'I' {
+                ans.push(low);
                 low += 1;
-                low
             } else {
+                ans.push(high);
                 high -= 1;
-                high
-            });
+            }
         }
-        res.push(low + 1);
-        res
+
+        ans.push(low);
+        ans
     }
 }

solution/0900-0999/0942.DI String Match/Solution.ts

@@ -1,15 +1,13 @@
 function diStringMatch(s: string): number[] {
-    const n = s.length;
-    const res = new Array(n + 1);
-    let low = 0;
-    let high = n;
-    for (let i = 0; i < n; i++) {
-        if (s[i] === 'I') {
-            res[i] = low++;
+    const ans: number[] = [];
+    let [low, high] = [0, s.length];
+    for (const c of s) {
+        if (c === 'I') {
+            ans.push(low++);
         } else {
-            res[i] = high--;
+            ans.push(high--);
         }
     }
-    res[n] = low;
-    return res;
+    ans.push(low);
+    return ans;
 }