Updated tasks 221-1143

src/main/java/g0001_0100/s0006_zigzag_conversion/Solution.java

@@ -1,6 +1,6 @@
 package g0001_0100.s0006_zigzag_conversion;
 
-// #Medium #String #2024_01_04_Time_2_ms_(99.60%)_Space_44.7_MB_(38.67%)
+// #Medium #String #2024_11_17_Time_2_ms_(99.71%)_Space_44.5_MB_(94.69%)
 
 public class Solution {
     public String convert(String s, int numRows) {

src/main/java/g0201_0300/s0221_maximal_square/Solution.java

@@ -1,7 +1,7 @@
 package g0201_0300.s0221_maximal_square;
 
 // #Medium #Array #Dynamic_Programming #Matrix #Dynamic_Programming_I_Day_16
-// #Big_O_Time_O(m*n)_Space_O(m*n) #2022_07_04_Time_7_ms_(72.35%)_Space_59.5_MB_(10.55%)
+// #Big_O_Time_O(m*n)_Space_O(m*n) #2024_11_16_Time_6_ms_(97.07%)_Space_60.3_MB_(39.55%)
 
 public class Solution {
     public int maximalSquare(char[][] matrix) {

src/main/java/g0201_0300/s0226_invert_binary_tree/Solution.java

@@ -2,7 +2,7 @@
 
 // #Easy #Top_100_Liked_Questions #Depth_First_Search #Breadth_First_Search #Tree #Binary_Tree
 // #Data_Structure_I_Day_12_Tree #Level_2_Day_6_Tree #Udemy_Tree_Stack_Queue
-// #Big_O_Time_O(n)_Space_O(n) #2022_07_04_Time_0_ms_(100.00%)_Space_42_MB_(20.73%)
+// #Big_O_Time_O(n)_Space_O(n) #2024_11_16_Time_0_ms_(100.00%)_Space_40.6_MB_(95.51%)
 
 import com_github_leetcode.TreeNode;
 

src/main/java/g0201_0300/s0230_kth_smallest_element_in_a_bst/Solution.java

@@ -2,7 +2,7 @@
 
 // #Medium #Top_100_Liked_Questions #Depth_First_Search #Tree #Binary_Tree #Binary_Search_Tree
 // #Data_Structure_II_Day_17_Tree #Level_2_Day_9_Binary_Search_Tree #Big_O_Time_O(n)_Space_O(n)
-// #2022_07_04_Time_1_ms_(78.91%)_Space_45.3_MB_(58.87%)
+// #2024_11_16_Time_0_ms_(100.00%)_Space_44.3_MB_(63.70%)
 
 import com_github_leetcode.TreeNode;
 

src/main/java/g0201_0300/s0234_palindrome_linked_list/Solution.java

@@ -2,7 +2,7 @@
 
 // #Easy #Top_100_Liked_Questions #Two_Pointers #Stack #Linked_List #Recursion
 // #Level_2_Day_3_Linked_List #Udemy_Linked_List #Big_O_Time_O(n)_Space_O(1)
-// #2022_07_04_Time_6_ms_(76.07%)_Space_97.6_MB_(56.14%)
+// #2024_11_16_Time_4_ms_(84.46%)_Space_69_MB_(17.17%)
 
 import com_github_leetcode.ListNode;
 

src/main/java/g0201_0300/s0236_lowest_common_ancestor_of_a_binary_tree/Solution.java

@@ -2,7 +2,7 @@
 
 // #Medium #Top_100_Liked_Questions #Depth_First_Search #Tree #Binary_Tree
 // #Data_Structure_II_Day_18_Tree #Udemy_Tree_Stack_Queue #Big_O_Time_O(n)_Space_O(n)
-// #2022_07_04_Time_10_ms_(56.51%)_Space_47.4_MB_(45.84%)
+// #2024_11_16_Time_6_ms_(100.00%)_Space_44_MB_(98.99%)
 
 import com_github_leetcode.TreeNode;
 

src/main/java/g0201_0300/s0238_product_of_array_except_self/Solution.java

@@ -1,28 +1,21 @@
 package g0201_0300.s0238_product_of_array_except_self;
 
 // #Medium #Top_100_Liked_Questions #Array #Prefix_Sum #Data_Structure_II_Day_5_Array #Udemy_Arrays
-// #Big_O_Time_O(n^2)_Space_O(n) #2022_07_04_Time_1_ms_(100.00%)_Space_50.8_MB_(85.60%)
+// #Big_O_Time_O(n^2)_Space_O(n) #2024_11_16_Time_1_ms_(99.66%)_Space_55.1_MB_(79.02%)
 
 public class Solution {
     public int[] productExceptSelf(int[] nums) {
-        int product = 1;
-        int[] ans = new int[nums.length];
-        for (int num : nums) {
-            product = product * num;
-        }
+        int[] res = new int[nums.length];
+        int prefixProduct = 1;
         for (int i = 0; i < nums.length; i++) {
-            if (nums[i] != 0) {
-                ans[i] = product / nums[i];
-            } else {
-                int p = 1;
-                for (int j = 0; j < nums.length; j++) {
-                    if (j != i) {
-                        p = p * nums[j];
-                    }
-                }
-                ans[i] = p;
-            }
+            res[i] = prefixProduct;
+            prefixProduct *= nums[i];
+        }
+        int suffixProduct = 1;
+        for (int i = nums.length - 1; i >= 0; i--) {
+            res[i] *= suffixProduct;
+            suffixProduct *= nums[i];
         }
-        return ans;
+        return res;
     }
 }

src/main/java/g0201_0300/s0239_sliding_window_maximum/Solution.java

@@ -2,7 +2,7 @@
 
 // #Hard #Top_100_Liked_Questions #Array #Heap_Priority_Queue #Sliding_Window #Queue
 // #Monotonic_Queue #Udemy_Arrays #Big_O_Time_O(n*k)_Space_O(n+k)
-// #2022_07_04_Time_58_ms_(52.28%)_Space_145_MB_(50.60%)
+// #2024_11_16_Time_26_ms_(95.89%)_Space_59.6_MB_(38.70%)
 
 import java.util.LinkedList;
 

src/main/java/g0201_0300/s0240_search_a_2d_matrix_ii/Solution.java

@@ -2,7 +2,7 @@
 
 // #Medium #Top_100_Liked_Questions #Array #Binary_Search #Matrix #Divide_and_Conquer
 // #Data_Structure_II_Day_4_Array #Binary_Search_II_Day_8 #Big_O_Time_O(n+m)_Space_O(1)
-// #2022_07_04_Time_7_ms_(86.73%)_Space_58.4_MB_(9.95%)
+// #2024_11_16_Time_5_ms_(99.92%)_Space_45.8_MB_(60.21%)
 
 public class Solution {
     public boolean searchMatrix(int[][] matrix, int target) {

src/main/java/g0201_0300/s0283_move_zeroes/Solution.java

@@ -2,7 +2,7 @@
 
 // #Easy #Top_100_Liked_Questions #Array #Two_Pointers #Algorithm_I_Day_3_Two_Pointers
 // #Programming_Skills_I_Day_6_Array #Udemy_Arrays #Big_O_Time_O(n)_Space_O(1)
-// #2022_07_06_Time_2_ms_(79.54%)_Space_55.7_MB_(5.98%)
+// #2024_11_16_Time_2_ms_(83.99%)_Space_45.9_MB_(50.99%)
 
 public class Solution {
     public void moveZeroes(int[] nums) {

src/main/java/g0201_0300/s0287_find_the_duplicate_number/Solution.java

@@ -2,7 +2,7 @@
 
 // #Medium #Top_100_Liked_Questions #Array #Binary_Search #Two_Pointers #Bit_Manipulation
 // #Binary_Search_II_Day_5 #Big_O_Time_O(n)_Space_O(n)
-// #2022_07_06_Time_2_ms_(99.82%)_Space_61.1_MB_(83.92%)
+// #2024_11_16_Time_2_ms_(97.52%)_Space_59.9_MB_(5.22%)
 
 public class Solution {
     public int findDuplicate(int[] nums) {

src/main/java/g0201_0300/s0295_find_median_from_data_stream/MedianFinder.java

@@ -1,7 +1,7 @@
 package g0201_0300.s0295_find_median_from_data_stream;
 
 // #Hard #Top_100_Liked_Questions #Sorting #Two_Pointers #Design #Heap_Priority_Queue #Data_Stream
-// #Big_O_Time_O(n*log_n)_Space_O(n) #2022_07_06_Time_151_ms_(80.24%)_Space_125.2_MB_(44.11%)
+// #Big_O_Time_O(n*log_n)_Space_O(n) #2024_11_16_Time_83_ms_(99.56%)_Space_63.4_MB_(77.85%)
 
 import java.util.PriorityQueue;
 

src/main/java/g0201_0300/s0300_longest_increasing_subsequence/Solution.java

@@ -3,7 +3,7 @@
 // #Medium #Top_100_Liked_Questions #Array #Dynamic_Programming #Binary_Search
 // #Algorithm_II_Day_16_Dynamic_Programming #Binary_Search_II_Day_3 #Dynamic_Programming_I_Day_18
 // #Udemy_Dynamic_Programming #Big_O_Time_O(n*log_n)_Space_O(n)
-// #2022_07_06_Time_3_ms_(98.63%)_Space_44.3_MB_(60.27%)
+// #2024_11_16_Time_3_ms_(95.75%)_Space_43.7_MB_(93.58%)
 
 public class Solution {
     public int lengthOfLIS(int[] nums) {

src/main/java/g0301_0400/s0322_coin_change/Solution.java

@@ -3,7 +3,7 @@
 // #Medium #Top_100_Liked_Questions #Array #Dynamic_Programming #Breadth_First_Search
 // #Algorithm_II_Day_18_Dynamic_Programming #Dynamic_Programming_I_Day_20
 // #Level_2_Day_12_Dynamic_Programming #Big_O_Time_O(m*n)_Space_O(amount)
-// #2022_07_09_Time_17_ms_(91.77%)_Space_41.8_MB_(95.50%)
+// #2024_11_16_Time_12_ms_(92.59%)_Space_44.3_MB_(64.02%)
 
 public class Solution {
     public int coinChange(int[] coins, int amount) {

src/main/java/g0301_0400/s0338_counting_bits/Solution.java

@@ -1,7 +1,7 @@
 package g0301_0400.s0338_counting_bits;
 
 // #Easy #Dynamic_Programming #Bit_Manipulation #Udemy_Bit_Manipulation
-// #Big_O_Time_O(num)_Space_O(num) #2022_07_10_Time_2_ms_(86.73%)_Space_48.3_MB_(31.59%)
+// #Big_O_Time_O(num)_Space_O(num) #2024_11_16_Time_2_ms_(96.37%)_Space_46.4_MB_(70.53%)
 
 public class Solution {
     public int[] countBits(int num) {

src/main/java/g0301_0400/s0347_top_k_frequent_elements/Solution.java

@@ -2,7 +2,7 @@
 
 // #Medium #Top_100_Liked_Questions #Array #Hash_Table #Sorting #Heap_Priority_Queue #Counting
 // #Divide_and_Conquer #Quickselect #Bucket_Sort #Data_Structure_II_Day_20_Heap_Priority_Queue
-// #Big_O_Time_O(n*log(n))_Space_O(k) #2022_07_11_Time_9_ms_(97.93%)_Space_48.5_MB_(83.34%)
+// #Big_O_Time_O(n*log(n))_Space_O(k) #2024_11_17_Time_9_ms_(97.30%)_Space_45.4_MB_(92.52%)
 
 import java.util.Arrays;
 import java.util.PriorityQueue;

src/main/java/g0301_0400/s0394_decode_string/Solution.java

@@ -1,7 +1,7 @@
 package g0301_0400.s0394_decode_string;
 
 // #Medium #Top_100_Liked_Questions #String #Stack #Recursion #Level_1_Day_14_Stack #Udemy_Strings
-// #Big_O_Time_O(n)_Space_O(n) #2022_07_15_Time_1_ms_(87.68%)_Space_41.2_MB_(83.30%)
+// #Big_O_Time_O(n)_Space_O(n) #2024_11_17_Time_0_ms_(100.00%)_Space_41.5_MB_(58.38%)
 
 public class Solution {
     private int i = 0;

src/main/java/g0401_0500/s0416_partition_equal_subset_sum/Solution.java

@@ -1,25 +1,33 @@
 package g0401_0500.s0416_partition_equal_subset_sum;
 
 // #Medium #Top_100_Liked_Questions #Array #Dynamic_Programming #Level_2_Day_13_Dynamic_Programming
-// #Big_O_Time_O(n*sums)_Space_O(n*sums) #2022_12_29_Time_27_ms_(94.53%)_Space_41.8_MB_(95.29%)
+// #Big_O_Time_O(n*sums)_Space_O(n*sums) #2024_11_17_Time_5_ms_(99.88%)_Space_42.2_MB_(85.79%)
 
 public class Solution {
     public boolean canPartition(int[] nums) {
-        int sums = 0;
-        for (int num : nums) {
-            sums += num;
+        int sum = 0;
+        for (int val : nums) {
+            sum += val;
         }
-        if (sums % 2 == 1) {
+        if (sum % 2 != 0) {
             return false;
         }
-        sums /= 2;
-        boolean[] dp = new boolean[sums + 1];
-        dp[0] = true;
-        for (int num : nums) {
-            for (int sum = sums; sum >= num; sum--) {
-                dp[sum] = dp[sum] || dp[sum - num];
+        sum /= 2;
+        boolean[] set = new boolean[sum + 1];
+        int[] arr = new int[sum + 2];
+        int top = 0;
+        for (int val : nums) {
+            for (int i = top; i > -1; i--) {
+                int tempSum = val + arr[i];
+                if (tempSum <= sum && !set[tempSum]) {
+                    if (tempSum == sum) {
+                        return true;
+                    }
+                    set[tempSum] = true;
+                    arr[++top] = tempSum;
+                }
             }
         }
-        return dp[sums];
+        return false;
     }
 }

src/main/java/g0401_0500/s0437_path_sum_iii/Solution.java

@@ -1,9 +1,10 @@
 package g0401_0500.s0437_path_sum_iii;
 
 // #Medium #Depth_First_Search #Tree #Binary_Tree #Level_2_Day_7_Tree #Big_O_Time_O(n)_Space_O(n)
-// #2022_07_16_Time_18_ms_(45.66%)_Space_42_MB_(88.96%)
+// #2024_11_17_Time_2_ms_(100.00%)_Space_44.7_MB_(11.66%)
 
 import com_github_leetcode.TreeNode;
+import java.util.HashMap;
 
 /*
  * Definition for a binary tree node.
@@ -21,28 +22,27 @@
  * }
  */
 public class Solution {
-    private int count = 0;
-
     public int pathSum(TreeNode root, int targetSum) {
-        if (root == null) {
-            return 0;
-        }
-        helper(root, targetSum, 0);
-        pathSum(root.left, targetSum);
-        pathSum(root.right, targetSum);
-        return count;
+        HashMap<Long, Integer> h = new HashMap<>();
+        return dfs(root, targetSum, h, 0L);
     }
 
-    public void helper(TreeNode node, int targetSum, long currSum) {
-        currSum += node.val;
-        if (targetSum == currSum) {
-            count++;
+    int dfs(TreeNode root, int t, HashMap<Long, Integer> h, Long cs) {
+        int s = 0;
+        if (root == null) {
+            return 0;
         }
-        if (node.left != null) {
-            helper(node.left, targetSum, currSum);
+        Long k = cs + root.val;
+        if (k == t) {
+            s += 1;
         }
-        if (node.right != null) {
-            helper(node.right, targetSum, currSum);
+        if (h.getOrDefault(k - t, 0) > 0) {
+            s += h.get(k - t);
         }
+        h.put(k, h.getOrDefault(k, 0) + 1);
+        s += dfs(root.left, t, h, k);
+        s += dfs(root.right, t, h, k);
+        h.put(k, h.getOrDefault(k, 0) - 1);
+        return s;
     }
 }

src/main/java/g0401_0500/s0438_find_all_anagrams_in_a_string/Solution.java

@@ -3,7 +3,7 @@
 // #Medium #Top_100_Liked_Questions #String #Hash_Table #Sliding_Window
 // #Algorithm_II_Day_5_Sliding_Window #Programming_Skills_II_Day_12
 // #Level_1_Day_12_Sliding_Window/Two_Pointer #Big_O_Time_O(n+m)_Space_O(1)
-// #2022_07_16_Time_6_ms_(99.03%)_Space_47.9_MB_(50.50%)
+// #2024_11_17_Time_3_ms_(99.83%)_Space_44.7_MB_(74.83%)
 
 import java.util.ArrayList;
 import java.util.List;

src/main/java/g0401_0500/s0494_target_sum/Solution.java

@@ -1,37 +1,45 @@
 package g0401_0500.s0494_target_sum;
 
 // #Medium #Array #Dynamic_Programming #Backtracking #Big_O_Time_O(n*(sum+s))_Space_O(n*(sum+s))
-// #2022_07_21_Time_9_ms_(79.99%)_Space_45.2_MB_(32.79%)
+// #2024_11_17_Time_4_ms_(92.28%)_Space_42.7_MB_(57.04%)
 
 public class Solution {
-    public int findTargetSumWays(int[] nums, int s) {
-        int sum = 0;
-        s = Math.abs(s);
-        for (int num : nums) {
-            sum += num;
+    public int findTargetSumWays(int[] nums, int target) {
+        int totalSum = 0;
+        int n = nums.length;
+        for (int i = 0; i < n; i++) {
+            totalSum += nums[i];
         }
-        // Invalid s, just return 0
-        if (s > sum || (sum + s) % 2 != 0) {
+        int sum = totalSum - target;
+        if (sum < 0 || sum % 2 == 1) {
             return 0;
         }
-        int[][] dp = new int[(sum + s) / 2 + 1][nums.length + 1];
-        dp[0][0] = 1;
-        // empty knapsack must be processed specially
-        for (int i = 0; i < nums.length; i++) {
-            if (nums[i] == 0) {
-                dp[0][i + 1] = dp[0][i] * 2;
-            } else {
-                dp[0][i + 1] = dp[0][i];
-            }
+        return solve(nums, sum / 2);
+    }
+
+    private int solve(int[] nums, int target) {
+        int[] prev = new int[target + 1];
+        if (nums[0] == 0) {
+            prev[0] = 2;
+        } else {
+            prev[0] = 1;
+        }
+        if (nums[0] != 0 && nums[0] <= target) {
+            prev[nums[0]] = 1;
         }
-        for (int i = 1; i < dp.length; i++) {
-            for (int j = 0; j < nums.length; j++) {
-                dp[i][j + 1] += dp[i][j];
-                if (nums[j] <= i) {
-                    dp[i][j + 1] += dp[i - nums[j]][j];
+        int n = nums.length;
+        for (int i = 1; i < n; i++) {
+            int[] curr = new int[target + 1];
+            for (int j = 0; j <= target; j++) {
+                int taken = 0;
+                if (j >= nums[i]) {
+                    taken = prev[j - nums[i]];
                 }
+                int nonTaken = prev[j];
+                curr[j] = taken + nonTaken;
             }
+            prev = curr;
         }
-        return dp[(sum + s) / 2][nums.length];
+        return prev[target];
     }
 }

src/main/java/g0501_0600/s0543_diameter_of_binary_tree/Solution.java

@@ -2,7 +2,7 @@
 
 // #Easy #Top_100_Liked_Questions #Depth_First_Search #Tree #Binary_Tree #Level_2_Day_7_Tree
 // #Udemy_Tree_Stack_Queue #Big_O_Time_O(n)_Space_O(n)
-// #2022_08_02_Time_1_ms_(65.86%)_Space_43.5_MB_(33.52%)
+// #2024_11_17_Time_0_ms_(100.00%)_Space_44.5_MB_(74.23%)
 
 import com_github_leetcode.TreeNode;
 

src/main/java/g0501_0600/s0560_subarray_sum_equals_k/Solution.java

@@ -1,7 +1,7 @@
 package g0501_0600.s0560_subarray_sum_equals_k;
 
 // #Medium #Top_100_Liked_Questions #Array #Hash_Table #Prefix_Sum #Data_Structure_II_Day_5_Array
-// #Big_O_Time_O(n)_Space_O(n) #2022_08_03_Time_21_ms_(98.97%)_Space_46.8_MB_(88.27%)
+// #Big_O_Time_O(n)_Space_O(n) #2024_11_17_Time_22_ms_(95.17%)_Space_47.2_MB_(6.13%)
 
 import java.util.HashMap;
 import java.util.Map;

src/main/java/g0601_0700/s0647_palindromic_substrings/Solution.java

@@ -1,7 +1,7 @@
 package g0601_0700.s0647_palindromic_substrings;
 
 // #Medium #String #Dynamic_Programming #Big_O_Time_O(n^2)_Space_O(n)
-// #2022_03_21_Time_2_ms_(98.77%)_Space_41.7_MB_(75.10%)
+// #2024_11_17_Time_2_ms_(99.31%)_Space_41.4_MB_(77.04%)
 
 public class Solution {
     private void expand(char[] a, int l, int r, int[] res) {

src/main/java/g0701_0800/s0739_daily_temperatures/Solution.java

@@ -1,7 +1,7 @@
 package g0701_0800.s0739_daily_temperatures;
 
 // #Medium #Top_100_Liked_Questions #Array #Stack #Monotonic_Stack #Programming_Skills_II_Day_6
-// #Big_O_Time_O(n)_Space_O(n) #2022_03_25_Time_10_ms_(94.99%)_Space_118.3_MB_(70.21%)
+// #Big_O_Time_O(n)_Space_O(n) #2024_11_17_Time_8_ms_(96.83%)_Space_60.6_MB_(55.93%)
 
 @SuppressWarnings("java:S135")
 public class Solution {