leetcode

Author: ayoubzulfiqar

CheckIfTwoStringArraysAreEquivalent/check_if_two_string_arrays_are_equivalent.dart

@@ -0,0 +1,119 @@
+/*
+
+
+ -* Check If Two String Arrays are Equivalent *-
+
+
+ Given two string arrays word1 and word2, return true if the two arrays represent the same string, and false otherwise.
+
+A string is represented by an array if the array elements concatenated in order forms the string.
+
+
+
+Example 1:
+
+Input: word1 = ["ab", "c"], word2 = ["a", "bc"]
+Output: true
+Explanation:
+word1 represents string "ab" + "c" -> "abc"
+word2 represents string "a" + "bc" -> "abc"
+The strings are the same, so return true.
+Example 2:
+
+Input: word1 = ["a", "cb"], word2 = ["ab", "c"]
+Output: false
+Example 3:
+
+Input: word1  = ["abc", "d", "defg"], word2 = ["abcddefg"]
+Output: true
+
+
+Constraints:
+
+1 <= word1.length, word2.length <= 103
+1 <= word1[i].length, word2[i].length <= 103
+1 <= sum(word1[i].length), sum(word2[i].length) <= 103
+word1[i] and word2[i] consist of lowercase letters.
+
+
+*/
+
+class A {
+// Runtime: 422 ms, faster than 83.33% of Dart online submissions for Check If Two String Arrays are Equivalent.
+// Memory Usage: 141.7 MB, less than 33.33% of Dart online submissions for Check If Two String Arrays are Equivalent.
+  bool arrayStringsAreEqual(List<String> word1, List<String> word2) {
+    return word1.join("") == word2.join("");
+  }
+}
+
+class B {
+// Runtime: 505 ms, faster than 33.33% of Dart online submissions for Check If Two String Arrays are Equivalent.
+// Memory Usage: 141.4 MB, less than 66.67% of Dart online submissions for Check If Two String Arrays are Equivalent.
+  bool arrayStringsAreEqual(List<String> word1, List<String> word2) {
+    int wordIdx1 = 0, wordIdx2 = 0, chIdx1 = 0, chIdx2 = 0;
+    while (true) {
+      int ch1 = word1[wordIdx1][chIdx1].codeUnitAt(0);
+      int ch2 = word2[wordIdx2][chIdx2].codeUnitAt(0);
+      if (ch1 != ch2) return false;
+
+      chIdx1++;
+      chIdx2++;
+      if (chIdx1 == word1[wordIdx1].length) {
+        wordIdx1++;
+        chIdx1 = 0;
+      }
+      if (chIdx2 == word2[wordIdx2].length) {
+        wordIdx2++;
+        chIdx2 = 0;
+      }
+
+      if (wordIdx1 == word1.length && wordIdx2 == word2.length) break;
+      if (wordIdx1 == word1.length || wordIdx2 == word2.length) return false;
+    }
+    return true;
+  }
+}
+
+class C {
+  bool arrayStringsAreEqual(List<String> word1, List<String> word2) {
+    int firstPointer = 0, secondPointer = 0; // inner pointer
+    int firstWord = 0, secondWord = 0; // outer pointer
+
+    while (firstWord < word1.length && secondWord < word2.length) {
+      String firstString = word1[firstWord], secondString = word2[secondWord];
+
+      if (firstString.codeUnitAt(firstPointer) !=
+          secondString.codeUnitAt(secondPointer)) return false;
+
+      if (firstPointer < firstString.length - 1) {
+        firstPointer++;
+      } else {
+        firstPointer = 0;
+        firstWord++;
+      }
+
+      if (secondPointer < secondString.length - 1) {
+        secondPointer++;
+      } else {
+        secondPointer = 0;
+        secondWord++;
+      }
+    }
+
+    return firstWord == word1.length && secondWord == word2.length;
+  }
+}
+
+class D {
+  bool arrayStringsAreEqual(List<String> word1, List<String> word2) {
+    StringBuffer sb1 = StringBuffer();
+    StringBuffer sb2 = StringBuffer();
+    for (String s in word1) {
+      sb1.write(s);
+    }
+    for (String s in word2) {
+      sb2.write(s);
+    }
+    return sb1.toString() == (sb2.toString());
+  }
+}

CheckIfTwoStringArraysAreEquivalent/check_if_two_string_arrays_are_equivalent.go

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+package main
+
+import "strings"
+
+func arrayStringsAreEqual(word1 []string, word2 []string) bool {
+	return strings.Join(word1, "") == strings.Join(word2, "")
+}

CheckIfTwoStringArraysAreEquivalent/check_if_two_string_arrays_are_equivalent.md

@@ -0,0 +1,77 @@
+# 🔥 Check If Two String Arrays are Equivalent 🔥 || 3 Solutions || Simple Fast and Easy || with Explanation
+
+## Approach Used: Arrays traversal, String comparison
+
+### Explanation
+
+This a very basic question. It is a beginner-friendly question which requires not much logic. We simply need to combine all the substrings in the array into one combines string for both the arrays. The order of combining should not change. After we get both the combined substring, we’ll simply compare them and return true is all the characters match, otherwise false.
+
+### Complexity
+
+#### Space Complexity: O(m+n) where m and n will be total characters present in array1 and array2 respectively
+
+#### Time Complexity: O(a+b) where a and b are the length of both arrays
+
+## Solution - 1
+
+```dart
+class Solution {
+// Runtime: 422 ms, faster than 100.00% of Dart online submissions for Check If Two String Arrays are Equivalent.
+// Memory Usage: 141.7 MB, less than 33.33% of Dart online submissions for Check If Two String Arrays are Equivalent.
+  bool arrayStringsAreEqual(List<String> word1, List<String> word2) {
+    return word1.join("") == word2.join("");
+  }
+}
+```
+
+## Solution - 2
+
+```dart
+class Solution {
+  bool arrayStringsAreEqual(List<String> word1, List<String> word2) {
+    int firstPointer = 0, secondPointer = 0; // inner pointer
+    int firstWord = 0, secondWord = 0; // outer pointer
+
+    while (firstWord < word1.length && secondWord < word2.length) {
+      String firstString = word1[firstWord], secondString = word2[secondWord];
+
+      if (firstString.codeUnitAt(firstPointer) !=
+          secondString.codeUnitAt(secondPointer)) return false;
+
+      if (firstPointer < firstString.length - 1) {
+        firstPointer++;
+      } else {
+        firstPointer = 0;
+        firstWord++;
+      }
+
+      if (secondPointer < secondString.length - 1) {
+        secondPointer++;
+      } else {
+        secondPointer = 0;
+        secondWord++;
+      }
+    }
+
+    return firstWord == word1.length && secondWord == word2.length;
+  }
+}
+```
+
+## Solution - 3
+
+```dart
+class Solution {
+  bool arrayStringsAreEqual(List<String> word1, List<String> word2) {
+    StringBuffer sb1 = StringBuffer();
+    StringBuffer sb2 = StringBuffer();
+    for (String s in word1) {
+      sb1.write(s);
+    }
+    for (String s in word2) {
+      sb2.write(s);
+    }
+    return sb1.toString() == (sb2.toString());
+  }
+}
+```

README.md

@@ -107,6 +107,7 @@ This repo contain leetcode solution using DART and GO programming language. Most
 - [Minimum Window Substring](MinimumWindowSubstring/minimum_window_substring.dart)
 - [Set Mismatch](SetMismatch/set_mismatch.dart)
 - [Maximum Length of a Concatenated String with Unique Characters](MaximumLengthOfAConcatenatedStringWithUniqueCharacters/maximum_length_of_a_concatenated_string_with_unique_characters.dart)
+- [Check If Two String Arrays are Equivalent](CheckIfTwoStringArraysAreEquivalent/check_if_two_string_arrays_are_equivalent.dart)
 
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