Updated tag for tasks 139-208

ThanhNIT · ThanhNIT · commit 0fbe1b2517bf · 2024-11-15T11:10:24.000+07:00
diff --git a/src/main/java/g0101_0200/s0139_word_break/Solution.java b/src/main/java/g0101_0200/s0139_word_break/Solution.java
@@ -3,43 +3,37 @@
 // #Medium #Top_100_Liked_Questions #Top_Interview_Questions #String #Hash_Table
 // #Dynamic_Programming #Trie #Memoization #Algorithm_II_Day_15_Dynamic_Programming
 // #Dynamic_Programming_I_Day_9 #Udemy_Dynamic_Programming #Big_O_Time_O(M+max*N)_Space_O(M+N+max)
-// #2022_06_24_Time_2_ms_(97.08%)_Space_42.1_MB_(90.92%)
+// #2024_11_15_Time_1_ms_(99.42%)_Space_42.1_MB_(80.42%)
 
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
 public class Solution {
+    Boolean[] memo;
     public boolean wordBreak(String s, List<String> wordDict) {
-        Set<String> set = new HashSet<>();
-        int max = 0;
-        boolean[] flag = new boolean[s.length() + 1];
-        for (String st : wordDict) {
-            set.add(st);
-            if (max < st.length()) {
-                max = st.length();
-            }
-        }
-        for (int i = 1; i <= max; i++) {
-            if (dfs(s, 0, i, max, set, flag)) {
-                return true;
-            }
-        }
-        return false;
+        memo = new Boolean[s.length() + 1];
+        return dp(s, 0, wordDict);
     }
 
-    private boolean dfs(String s, int start, int end, int max, Set<String> set, boolean[] flag) {
-        if (!flag[end] && set.contains(s.substring(start, end))) {
-            flag[end] = true;
-            if (end == s.length()) {
-                return true;
+    public boolean dp(String s, int i, List<String> wordDict){
+        if(i == s.length()) return true;
+        if(memo[i] != null) return memo[i];
+        for(String word: wordDict){
+            int len = word.length();
+            if(i + len > s.length()){
+                continue;
             }
-            for (int i = 1; i <= max; i++) {
-                if (end + i <= s.length() && dfs(s, end, end + i, max, set, flag)) {
-                    return true;
-                }
+            String subStr = s.substring(i, i + len);
+            if(!subStr.equals(word)){
+                continue;
+            }
+            if(dp(s, i + len, wordDict)){
+                memo[i] = true;
+                return true;
             }
         }
+        memo[i] = false;
         return false;
     }
 }
diff --git a/src/main/java/g0101_0200/s0141_linked_list_cycle/Solution.java b/src/main/java/g0101_0200/s0141_linked_list_cycle/Solution.java
@@ -2,7 +2,7 @@
 
 // #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Hash_Table #Two_Pointers #Linked_List
 // #Data_Structure_I_Day_7_Linked_List #Udemy_Linked_List #Big_O_Time_O(N)_Space_O(1)
-// #2022_06_24_Time_0_ms_(100.00%)_Space_45.5_MB_(68.52%)
+// #2024_11_15_Time_0_ms_(100.00%)_Space_44.3_MB_(52.46%)
 
 import com_github_leetcode.ListNode;
 
diff --git a/src/main/java/g0101_0200/s0142_linked_list_cycle_ii/Solution.java b/src/main/java/g0101_0200/s0142_linked_list_cycle_ii/Solution.java
@@ -2,7 +2,7 @@
 
 // #Medium #Top_100_Liked_Questions #Hash_Table #Two_Pointers #Linked_List
 // #Data_Structure_II_Day_10_Linked_List #Level_1_Day_4_Linked_List #Udemy_Linked_List
-// #Big_O_Time_O(N)_Space_O(1) #2022_06_24_Time_0_ms_(100.00%)_Space_42.3_MB_(98.70%)
+// #Big_O_Time_O(N)_Space_O(1) #2024_11_15_Time_0_ms_(100.00%)_Space_44.7_MB_(20.31%)
 
 import com_github_leetcode.ListNode;
 
diff --git a/src/main/java/g0101_0200/s0146_lru_cache/LRUCache.java b/src/main/java/g0101_0200/s0146_lru_cache/LRUCache.java
@@ -2,7 +2,7 @@
 
 // #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Hash_Table #Design #Linked_List
 // #Doubly_Linked_List #Udemy_Linked_List #Big_O_Time_O(1)_Space_O(capacity)
-// #2022_06_24_Time_87_ms_(50.80%)_Space_125.2_MB_(58.73%)
+// #2024_11_15_Time_40_ms_(98.20%)_Space_111.4_MB_(88.70%)
 
 import java.util.HashMap;
 import java.util.Map;
diff --git a/src/main/java/g0101_0200/s0148_sort_list/Solution.java b/src/main/java/g0101_0200/s0148_sort_list/Solution.java
@@ -2,7 +2,7 @@
 
 // #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Sorting #Two_Pointers #Linked_List
 // #Divide_and_Conquer #Merge_Sort #Level_2_Day_4_Linked_List #Big_O_Time_O(log(N))_Space_O(log(N))
-// #2022_06_24_Time_12_ms_(85.82%)_Space_76_MB_(43.84%)
+// #2024_11_15_Time_9_ms_(93.90%)_Space_56.9_MB_(37.47%)
 
 import com_github_leetcode.ListNode;
 
diff --git a/src/main/java/g0101_0200/s0152_maximum_product_subarray/Solution.java b/src/main/java/g0101_0200/s0152_maximum_product_subarray/Solution.java
@@ -2,23 +2,24 @@
 
 // #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Dynamic_Programming
 // #Dynamic_Programming_I_Day_6 #Level_2_Day_13_Dynamic_Programming #Udemy_Dynamic_Programming
-// #Big_O_Time_O(N)_Space_O(1) #2024_07_03_Time_1_ms_(92.31%)_Space_44.6_MB_(75.65%)
+// #Big_O_Time_O(N)_Space_O(1) #2024_11_15_Time_1_ms_(92.74%)_Space_45_MB_(23.41%)
 
 public class Solution {
     public int maxProduct(int[] nums) {
-        int currentMaxProd = nums[0];
-        int currentMinProd = nums[0];
-        int overAllMaxProd = nums[0];
-        for (int i = 1; i < nums.length; i++) {
-            if (nums[i] < 0) {
-                int temp = currentMaxProd;
-                currentMaxProd = currentMinProd;
-                currentMinProd = temp;
-            }
-            currentMaxProd = Math.max(nums[i], nums[i] * currentMaxProd);
-            currentMinProd = Math.min(nums[i], nums[i] * currentMinProd);
-            overAllMaxProd = Math.max(overAllMaxProd, currentMaxProd);
+        int m=Integer.MIN_VALUE;
+        int n=nums.length;
+        int start=1;
+        int end=1;
+        for(int i=0;i<n;i++){
+            if(start==0)
+                start=1;
+            if (end==0)
+                end=1;
+            start=start*nums[i];
+            end=end*nums[n-i-1];
+            m=Math.max(m,Math.max(start,end));
+
         }
-        return overAllMaxProd;
+        return m;
     }
 }
diff --git a/src/main/java/g0101_0200/s0153_find_minimum_in_rotated_sorted_array/Solution.java b/src/main/java/g0101_0200/s0153_find_minimum_in_rotated_sorted_array/Solution.java
@@ -2,7 +2,7 @@
 
 // #Medium #Top_100_Liked_Questions #Array #Binary_Search #Algorithm_II_Day_2_Binary_Search
 // #Binary_Search_I_Day_12 #Udemy_Binary_Search #Big_O_Time_O(log_N)_Space_O(log_N)
-// #2022_06_25_Time_0_ms_(100.00%)_Space_43.3_MB_(6.36%)
+// #2024_11_15_Time_0_ms_(100.00%)_Space_42.1_MB_(33.31%)
 
 public class Solution {
     private int findMinUtil(int[] nums, int l, int r) {
diff --git a/src/main/java/g0101_0200/s0155_min_stack/MinStack.java b/src/main/java/g0101_0200/s0155_min_stack/MinStack.java
@@ -2,7 +2,7 @@
 
 // #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Stack #Design
 // #Data_Structure_II_Day_14_Stack_Queue #Programming_Skills_II_Day_18 #Level_2_Day_16_Design
-// #Udemy_Design #Big_O_Time_O(1)_Space_O(N) #2022_06_25_Time_3_ms_(100.00%)_Space_44.3_MB_(85.39%)
+// #Udemy_Design #Big_O_Time_O(1)_Space_O(N) #2024_11_15_Time_4_ms_(96.54%)_Space_44.5_MB_(84.54%)
 
 public class MinStack {
     private static class Node {
diff --git a/src/main/java/g0101_0200/s0160_intersection_of_two_linked_lists/Solution.java b/src/main/java/g0101_0200/s0160_intersection_of_two_linked_lists/Solution.java
@@ -2,7 +2,7 @@
 
 // #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Hash_Table #Two_Pointers #Linked_List
 // #Data_Structure_II_Day_11_Linked_List #Udemy_Linked_List #Big_O_Time_O(M+N)_Space_O(1)
-// #2022_06_25_Time_1_ms_(99.68%)_Space_55.1_MB_(63.42%)
+// #2024_11_15_Time_1_ms_(99.92%)_Space_48.4_MB_(68.45%)
 
 import com_github_leetcode.ListNode;
 
diff --git a/src/main/java/g0101_0200/s0169_majority_element/Solution.java b/src/main/java/g0101_0200/s0169_majority_element/Solution.java
@@ -2,7 +2,7 @@
 
 // #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Array #Hash_Table #Sorting #Counting
 // #Divide_and_Conquer #Data_Structure_II_Day_1_Array #Udemy_Famous_Algorithm
-// #Big_O_Time_O(n)_Space_O(1) #2022_06_25_Time_1_ms_(100.00%)_Space_45.5_MB_(97.51%)
+// #Big_O_Time_O(n)_Space_O(1) #2024_11_15_Time_1_ms_(99.89%)_Space_52.8_MB_(64.33%)
 
 public class Solution {
     public int majorityElement(int[] arr) {
diff --git a/src/main/java/g0101_0200/s0189_rotate_array/Solution.java b/src/main/java/g0101_0200/s0189_rotate_array/Solution.java
@@ -2,7 +2,7 @@
 
 // #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Math #Two_Pointers
 // #Algorithm_I_Day_2_Two_Pointers #Udemy_Arrays #Big_O_Time_O(n)_Space_O(1)
-// #2022_06_27_Time_0_ms_(100.00%)_Space_58_MB_(96.22%)
+// #2024_11_15_Time_0_ms_(100.00%)_Space_57.7_MB_(14.36%)
 
 public class Solution {
     private void reverse(int[] nums, int l, int r) {
diff --git a/src/main/java/g0101_0200/s0198_house_robber/Solution.java b/src/main/java/g0101_0200/s0198_house_robber/Solution.java
@@ -3,7 +3,7 @@
 // #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Dynamic_Programming
 // #Algorithm_I_Day_12_Dynamic_Programming #Dynamic_Programming_I_Day_3
 // #Level_2_Day_12_Dynamic_Programming #Udemy_Dynamic_Programming #Big_O_Time_O(n)_Space_O(n)
-// #2022_06_28_Time_0_ms_(100.00%)_Space_39.9_MB_(85.30%)
+// #2024_11_15_Time_0_ms_(100.00%)_Space_40.7_MB_(77.55%)
 
 public class Solution {
     public int rob(int[] nums) {
diff --git a/src/main/java/g0101_0200/s0200_number_of_islands/Solution.java b/src/main/java/g0101_0200/s0200_number_of_islands/Solution.java
@@ -4,7 +4,7 @@
 // #Breadth_First_Search #Matrix #Union_Find
 // #Algorithm_II_Day_6_Breadth_First_Search_Depth_First_Search
 // #Graph_Theory_I_Day_1_Matrix_Related_Problems #Level_1_Day_9_Graph/BFS/DFS #Udemy_Graph
-// #Big_O_Time_O(M*N)_Space_O(M*N) #2022_06_28_Time_3_ms_(97.76%)_Space_57.5_MB_(41.23%)
+// #Big_O_Time_O(M*N)_Space_O(M*N) #2024_11_15_Time_3_ms_(87.24%)_Space_49.6_MB_(39.89%)
 
 public class Solution {
     public int numIslands(char[][] grid) {
diff --git a/src/main/java/g0201_0300/s0206_reverse_linked_list/Solution.java b/src/main/java/g0201_0300/s0206_reverse_linked_list/Solution.java
@@ -3,7 +3,7 @@
 // #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Linked_List #Recursion
 // #Data_Structure_I_Day_8_Linked_List #Algorithm_I_Day_10_Recursion_Backtracking
 // #Level_1_Day_3_Linked_List #Udemy_Linked_List #Big_O_Time_O(N)_Space_O(1)
-// #2022_06_28_Time_0_ms_(100.00%)_Space_43.9_MB_(7.98%)
+// #2024_11_15_Time_0_ms_(100.00%)_Space_42.5_MB_(41.63%)
 
 import com_github_leetcode.ListNode;
 
diff --git a/src/main/java/g0201_0300/s0207_course_schedule/Solution.java b/src/main/java/g0201_0300/s0207_course_schedule/Solution.java
@@ -2,7 +2,7 @@
 
 // #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Depth_First_Search
 // #Breadth_First_Search #Graph #Topological_Sort #Big_O_Time_O(N)_Space_O(N)
-// #2022_06_28_Time_3_ms_(97.58%)_Space_48.2_MB_(49.51%)
+// #2024_11_15_Time_3_ms_(99.99%)_Space_44.8_MB_(88.52%)
 
 import java.util.ArrayList;
 
diff --git a/src/main/java/g0201_0300/s0208_implement_trie_prefix_tree/Trie.java b/src/main/java/g0201_0300/s0208_implement_trie_prefix_tree/Trie.java
@@ -3,67 +3,119 @@
 // #Medium #Top_100_Liked_Questions #Top_Interview_Questions #String #Hash_Table #Design #Trie
 // #Level_2_Day_16_Design #Udemy_Trie_and_Heap
 // #Big_O_Time_O(word.length())_or_O(prefix.length())_Space_O(N)
-// #2022_06_28_Time_34_ms_(99.90%)_Space_51_MB_(94.92%)
+// #2024_11_15_Time_30_ms_(99.78%)_Space_55.1_MB_(72.51%)
 
 @SuppressWarnings("java:S1104")
 public class Trie {
-    private final TrieNode root;
-    private boolean startWith;
-
-    private static class TrieNode {
-        // Initialize your data structure here.
-        public TrieNode[] children;
-        public boolean isWord;
+    boolean ans=false;
+    TrieNode[] trees=new TrieNode[26];
+    public Trie() {
 
-        public TrieNode() {
-            children = new TrieNode[26];
-        }
     }
 
-    public Trie() {
-        root = new TrieNode();
+    TrieNode mapWordToTree(TrieNode t, String word, int i){
+        char m=word.charAt(i);
+        boolean found=false;
+        TrieNode a=t.nexts[m-'a'];
+        if(a!=null){
+            if(i!=word.length()-1){
+                mapWordToTree(a,word,i+1);
+                found=true;
+
+            }else{
+                a.end=true;
+                found=true;
+            }
+        }
+        if(!found){
+            TrieNode prev=t;
+            for(int j=i;j<word.length();j++){
+                TrieNode temp=new TrieNode(word.charAt(j));
+                prev.nexts[word.charAt(j)-'a']=temp;
+                prev=temp;
+            }
+            prev.end=true;
+        }
+        return t;
     }
 
-    // Inserts a word into the trie.
     public void insert(String word) {
-        insert(word, root, 0);
+        char a=word.charAt(0);
+        if(trees[a-'a']==null){
+            TrieNode t=new TrieNode(a);
+            trees[a-'a']=t;
+            if(1==word.length()){
+                trees[a-'a'].end=true;
+                return;
+            }
+            trees[a-'a']=mapWordToTree(trees[a-'a'],word,1);
+        }else{
+            if(1==word.length()){
+                trees[a-'a'].end=true;
+                return;
+            }
+            trees[a-'a']=mapWordToTree(trees[a-'a'],word,1);
+        }
+        //System.out.println(trees[a-'a']);
     }
+    public boolean searchWordInTree(TrieNode t, String word, int i){
+        char a=word.charAt(i);
+        TrieNode m=t.nexts[a-'a'];
+        if(m!=null){
+
+            if(i==word.length()-1){
+                ans=true;
+                if(m.end){
+                    return true;
+                }else{
+                    return false;
+                }
+            }
+            return searchWordInTree(m,word, i+1);
 
-    private void insert(String word, TrieNode root, int idx) {
-        if (idx == word.length()) {
-            root.isWord = true;
-            return;
-        }
-        int index = word.charAt(idx) - 'a';
-        if (root.children[index] == null) {
-            root.children[index] = new TrieNode();
         }
-        insert(word, root.children[index], idx + 1);
+        return false;
     }
-
-    // Returns if the word is in the trie.
     public boolean search(String word) {
-        return search(word, root, 0);
+        char a=word.charAt(0);
+        if(trees[a-'a']==null){
+            return false;
+        }else{
+            if(1==word.length()){
+                if(trees[a-'a'].end){
+                    return true;
+                }else{
+                    return false;
+                }
+            }
+            return searchWordInTree(trees[a-'a'],word,1);
+        }
     }
 
-    private boolean search(String word, TrieNode root, int idx) {
-        if (idx == word.length()) {
-            startWith = true;
-            return root.isWord;
-        }
-        int index = word.charAt(idx) - 'a';
-        if (root.children[index] == null) {
-            startWith = false;
+    public boolean startsWith(String prefix) {
+        char a=prefix.charAt(0);
+        ans=false;
+        if(trees[a-'a']==null){
             return false;
+        }else{
+            if(1==prefix.length()){
+                return true;
+            }
+            searchWordInTree(trees[a-'a'],prefix,1);
         }
-        return search(word, root.children[index], idx + 1);
+        return ans;
     }
 
-    // Returns if there is any word in the trie
-    // that starts with the given prefix.
-    public boolean startsWith(String prefix) {
-        search(prefix);
-        return startWith;
+    class TrieNode{
+        char val;
+        boolean end=false;
+        TrieNode[] nexts=new TrieNode[26];
+        TrieNode(char val){
+            this.val=val;
+        }
+        @Override public String toString(){
+            return val+" "+nexts+" "+end;
+        }
     }
 }
 
@@ -74,3 +126,11 @@ public boolean startsWith(String prefix) {
  * boolean param_2 = obj.search(word);
  * boolean param_3 = obj.startsWith(prefix);
  */
+
+/*
+ * Your Trie object will be instantiated and called as such:
+ * Trie obj = new Trie();
+ * obj.insert(word);
+ * boolean param_2 = obj.search(word);
+ * boolean param_3 = obj.startsWith(prefix);
+ */
