feat: add solutions to lc problem: No.1640

yanglbme · yanglbme · commit 2fd1c7b12502 · 2022-09-22T09:24:17.000+08:00
No.1640.Check Array Formation Through Concatenation
diff --git a/solution/1600-1699/1640.Check Array Formation Through Concatenation/README.md b/solution/1600-1699/1640.Check Array Formation Through Concatenation/README.md
@@ -52,7 +52,15 @@
 
 <!-- 这里可写通用的实现逻辑 -->
 
-**方法一：哈希表**
+**方法一：暴力枚举**
+
+遍历 `arr`，在 `pieces` 中找到首元素等于当前 `arr[i]` 的数组项，如果找不到，直接返回 `false`。
+
+如果找到了，我们记数组项为 `pieces[k]`，然后继续往后遍历 `arr[i]` 和 `pieces[k]`，直至 `pieces[k]` 遍历完或者元素不等。
+
+遍历结束，返回 `true`。
+
+**方法二：哈希表**
 
 创建一个哈希表，键为 `pieces` 中每个数组项的首元素，值为数组项。
 
@@ -68,6 +76,22 @@
 
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
+```python
+class Solution:
+    def canFormArray(self, arr: List[int], pieces: List[List[int]]) -> bool:
+        i = 0
+        while i < len(arr):
+            k = 0
+            while k < len(pieces) and pieces[k][0] != arr[i]:
+                k += 1
+            if k == len(pieces):
+                return False
+            j = 0
+            while j < len(pieces[k]) and arr[i] == pieces[k][j]:
+                i, j = i + 1, j + 1
+        return True
+```
+
 ```python
 class Solution:
     def canFormArray(self, arr: List[int], pieces: List[List[int]]) -> bool:
@@ -87,6 +111,28 @@ class Solution:
 
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
+```java
+class Solution {
+    public boolean canFormArray(int[] arr, int[][] pieces) {
+        for (int i = 0; i < arr.length;) {
+            int k = 0;
+            while (k < pieces.length && pieces[k][0] != arr[i]) {
+                ++k;
+            }
+            if (k == pieces.length) {
+                return false;
+            }
+            int j = 0;
+            while (j < pieces[k].length && arr[i] == pieces[k][j]) {
+                ++i;
+                ++j;
+            }
+        }
+        return true;
+    }
+}
+```
+
 ```java
 class Solution {
     public boolean canFormArray(int[] arr, int[][] pieces) {
@@ -98,7 +144,6 @@ class Solution {
             if (!d.containsKey(arr[i])) {
                 return false;
             }
-            var p = d.get(arr[i]);
             for (int v : d.get(arr[i])) {
                 if (arr[i++] != v) {
                     return false;
@@ -112,6 +157,31 @@ class Solution {
 
 ### **C++**
 
+### **C++**
+
+```cpp
+class Solution {
+public:
+    bool canFormArray(vector<int>& arr, vector<vector<int>>& pieces) {
+        for (int i = 0; i < arr.size();) {
+            int k = 0;
+            while (k < pieces.size() && pieces[k][0] != arr[i]) {
+                ++k;
+            }
+            if (k == pieces.size()) {
+                return false;
+            }
+            int j = 0;
+            while (j < pieces[k].size() && arr[i] == pieces[k][j]) {
+                ++i;
+                ++j;
+            }
+        }
+        return true;
+    }
+};
+```
+
 ```cpp
 class Solution {
 public:
@@ -124,8 +194,7 @@ public:
             if (!d.count(arr[i])) {
                 return false;
             }
-            auto& p = d[arr[i]];
-            for (int& v : p) {
+            for (int& v : d[arr[i]]) {
                 if (arr[i++] != v) {
                     return false;
                 }
@@ -138,6 +207,25 @@ public:
 
 ### **Go**
 
+```go
+func canFormArray(arr []int, pieces [][]int) bool {
+	for i := 0; i < len(arr); {
+		k := 0
+		for k < len(pieces) && pieces[k][0] != arr[i] {
+			k++
+		}
+		if k == len(pieces) {
+			return false
+		}
+		j := 0
+		for j < len(pieces[k]) && arr[i] == pieces[k][j] {
+			i, j = i+1, j+1
+		}
+	}
+	return true
+}
+```
+
 ```go
 func canFormArray(arr []int, pieces [][]int) bool {
 	d := map[int][]int{}
diff --git a/solution/1600-1699/1640.Check Array Formation Through Concatenation/README_EN.md b/solution/1600-1699/1640.Check Array Formation Through Concatenation/README_EN.md
@@ -51,6 +51,22 @@
 
 ### **Python3**
 
+```python
+class Solution:
+    def canFormArray(self, arr: List[int], pieces: List[List[int]]) -> bool:
+        i = 0
+        while i < len(arr):
+            k = 0
+            while k < len(pieces) and pieces[k][0] != arr[i]:
+                k += 1
+            if k == len(pieces):
+                return False
+            j = 0
+            while j < len(pieces[k]) and arr[i] == pieces[k][j]:
+                i, j = i + 1, j + 1
+        return True
+```
+
 ```python
 class Solution:
     def canFormArray(self, arr: List[int], pieces: List[List[int]]) -> bool:
@@ -68,6 +84,28 @@ class Solution:
 
 ### **Java**
 
+```java
+class Solution {
+    public boolean canFormArray(int[] arr, int[][] pieces) {
+        for (int i = 0; i < arr.length;) {
+            int k = 0;
+            while (k < pieces.length && pieces[k][0] != arr[i]) {
+                ++k;
+            }
+            if (k == pieces.length) {
+                return false;
+            }
+            int j = 0;
+            while (j < pieces[k].length && arr[i] == pieces[k][j]) {
+                ++i;
+                ++j;
+            }
+        }
+        return true;
+    }
+}
+```
+
 ```java
 class Solution {
     public boolean canFormArray(int[] arr, int[][] pieces) {
@@ -79,7 +117,6 @@ class Solution {
             if (!d.containsKey(arr[i])) {
                 return false;
             }
-            var p = d.get(arr[i]);
             for (int v : d.get(arr[i])) {
                 if (arr[i++] != v) {
                     return false;
@@ -93,6 +130,29 @@ class Solution {
 
 ### **C++**
 
+```cpp
+class Solution {
+public:
+    bool canFormArray(vector<int>& arr, vector<vector<int>>& pieces) {
+        for (int i = 0; i < arr.size();) {
+            int k = 0;
+            while (k < pieces.size() && pieces[k][0] != arr[i]) {
+                ++k;
+            }
+            if (k == pieces.size()) {
+                return false;
+            }
+            int j = 0;
+            while (j < pieces[k].size() && arr[i] == pieces[k][j]) {
+                ++i;
+                ++j;
+            }
+        }
+        return true;
+    }
+};
+```
+
 ```cpp
 class Solution {
 public:
@@ -105,8 +165,7 @@ public:
             if (!d.count(arr[i])) {
                 return false;
             }
-            auto& p = d[arr[i]];
-            for (int& v : p) {
+            for (int& v : d[arr[i]]) {
                 if (arr[i++] != v) {
                     return false;
                 }
@@ -119,6 +178,25 @@ public:
 
 ### **Go**
 
+```go
+func canFormArray(arr []int, pieces [][]int) bool {
+	for i := 0; i < len(arr); {
+		k := 0
+		for k < len(pieces) && pieces[k][0] != arr[i] {
+			k++
+		}
+		if k == len(pieces) {
+			return false
+		}
+		j := 0
+		for j < len(pieces[k]) && arr[i] == pieces[k][j] {
+			i, j = i+1, j+1
+		}
+	}
+	return true
+}
+```
+
 ```go
 func canFormArray(arr []int, pieces [][]int) bool {
 	d := map[int][]int{}
diff --git a/solution/1600-1699/1640.Check Array Formation Through Concatenation/Solution.cpp b/solution/1600-1699/1640.Check Array Formation Through Concatenation/Solution.cpp
@@ -9,8 +9,7 @@ class Solution {
             if (!d.count(arr[i])) {
                 return false;
             }
-            auto& p = d[arr[i]];
-            for (int& v : p) {
+            for (int& v : d[arr[i]]) {
                 if (arr[i++] != v) {
                     return false;
                 }
diff --git a/solution/1600-1699/1640.Check Array Formation Through Concatenation/Solution.java b/solution/1600-1699/1640.Check Array Formation Through Concatenation/Solution.java
@@ -8,7 +8,6 @@ public boolean canFormArray(int[] arr, int[][] pieces) {
             if (!d.containsKey(arr[i])) {
                 return false;
             }
-            var p = d.get(arr[i]);
             for (int v : d.get(arr[i])) {
                 if (arr[i++] != v) {
                     return false;

Original file line number	Diff line number	Diff line change
`@@ -9,8 +9,7 @@ class Solution {`
`9`	`9`	`if (!d.count(arr[i])) {`
`10`	`10`	`return false;`
`11`	`11`	`}`
`12`		`- auto& p = d[arr[i]];`
`13`		`- for (int& v : p) {`
	`12`	`+ for (int& v : d[arr[i]]) {`
`14`	`13`	`if (arr[i++] != v) {`
`15`	`14`	`return false;`
`16`	`15`	`}`
Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,6 @@ public boolean canFormArray(int[] arr, int[][] pieces) {`
`8`	`8`	`if (!d.containsKey(arr[i])) {`
`9`	`9`	`return false;`
`10`	`10`	`}`
`11`		`- var p = d.get(arr[i]);`
`12`	`11`	`for (int v : d.get(arr[i])) {`
`13`	`12`	`if (arr[i++] != v) {`
`14`	`13`	`return false;`