-
Notifications
You must be signed in to change notification settings - Fork 2
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
1 parent
02625ab
commit 4cd18dc
Showing
21 changed files
with
623 additions
and
62 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
105 changes: 105 additions & 0 deletions
105
src/com/problems/array/MinimumNumberOfOperationsToMakeElementsInArrayDistinct.java
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,105 @@ | ||
| package com.problems.array; | ||
|
|
||
| /* | ||
| * Problem link: | ||
| * https://leetcode.com/problems/minimum-number-of-operations-to-make-elements-in-array-distinct/ | ||
| * | ||
| * Solution link : | ||
| * | ||
| */ | ||
| public class MinimumNumberOfOperationsToMakeElementsInArrayDistinct { | ||
| public static void main(String[] args) { | ||
| type1(); | ||
| type2(); | ||
| type3(); | ||
| } | ||
|
|
||
| // rather going from first if we go from the last | ||
| // if we go from the last till freq of any element is greater than 1 | ||
| private static void type3() { | ||
| int[] nums = {1, 2, 3, 4, 2, 3, 3, 5, 7}; | ||
| int ans = minimumOperations3(nums); | ||
| System.out.println(ans); | ||
| } | ||
|
|
||
| private static int minimumOperations3(int[] nums) { | ||
| int n = nums.length; | ||
| int[] freq = new int[101]; | ||
| int rem = (n % 3); | ||
| int parts = (n / 3) + (rem > 0 ? 1 : 0); | ||
| int i = n - 1; | ||
| // checking for the first part individually if there is any reminder | ||
| while (rem > 0) { | ||
| rem--; | ||
| int num = nums[i--]; | ||
| freq[num]++; | ||
| if (freq[num] == 2) return parts; | ||
| } | ||
| // this means n has a reminder but that part only contained the unique elements, | ||
| // so we will decrement the part needed | ||
| if (n % 3 != 0) parts--; | ||
|
|
||
| // checking for the remaining parts which is multiple of length 3 | ||
| while (parts > 0) { | ||
| int d = 3; | ||
| while (d > 0) { | ||
| int num = nums[i--]; | ||
| freq[num]++; | ||
| if (freq[num] == 2) return parts; | ||
| d--; | ||
| } | ||
| parts--; | ||
| } | ||
| return parts; | ||
| } | ||
|
|
||
| // hashing approach | ||
| // we will store the freq of the numbers and as we well as store a variable to keep track | ||
| // the number of non-unique elements. so that we do not need to go through the entire freq map or array | ||
| // every time, to check how many non-unique are left | ||
| private static void type2() { | ||
| int[] nums = {1, 2, 3, 4, 2, 3, 3, 5, 7}; | ||
| int ans = minimumOperations2(nums); | ||
| System.out.println(ans); | ||
| } | ||
|
|
||
| public static int minimumOperations2(int[] nums) { | ||
| int n = nums.length; | ||
| int count = 0; | ||
| int[] freq = new int[101]; | ||
| int nonUnique = 0; | ||
| for (int num : nums) { | ||
| freq[num]++; | ||
| // if freq 2, that means it is non-unique, | ||
| // we do not need to check for > 2 as once it is non-unique, it will stay as non-unique | ||
| if (freq[num] == 2) nonUnique++; | ||
| } | ||
| // now we will loop till non-unique count is 0 | ||
| // (non-unique-count > 0) means there should be at least 2 elements in the array | ||
| int i = 0; | ||
| while (nonUnique > 0) { | ||
| count++; | ||
| int first = nums[i], second = nums[i + 1]; | ||
| // decreasing the freq of first and checking if the freq reduced to 1 | ||
| freq[first]--; | ||
| if (freq[first] == 1) nonUnique--; | ||
| // decreasing the freq of first and checking if the freq reduced to 1 | ||
| freq[second]--; | ||
| if (freq[second] == 1) nonUnique--; | ||
| // checking if there is the third element or not, if it has third then only we will check for it | ||
| if (i + 2 < n) { | ||
| int third = nums[i + 2]; | ||
| freq[third]--; | ||
| if (freq[third] == 1) nonUnique--; | ||
| } | ||
| i = i + 3; | ||
| } | ||
| return count; | ||
| } | ||
|
|
||
|
|
||
| // brute force approach | ||
| private static void type1() { | ||
| } | ||
|
|
||
| } |
52 changes: 52 additions & 0 deletions
52
src/com/problems/array/MinimumNumberOfSwapsToMakeTheStringBalanced.java
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,52 @@ | ||
| package com.problems.array; | ||
|
|
||
| /* | ||
| * | ||
| * problem links : | ||
| * https://leetcode.com/problems/minimum-number-of-swaps-to-make-the-string-balanced/description/ | ||
| * | ||
| * Solution link : | ||
| * https://www.youtube.com/watch?v=3YDBT9ZrfaU | ||
| * | ||
| * https://neetcode.io/solutions/minimum-number-of-swaps-to-make-the-string-balanced | ||
| * */ | ||
|
|
||
|
|
||
| // Tags: Arrays, Two Pointers, String, Stack, Greedy | ||
| public class MinimumNumberOfSwapsToMakeTheStringBalanced { | ||
| public static void main(String[] args) { | ||
| type1(); | ||
| } | ||
|
|
||
| // todo check this solution again | ||
| // We will be a little greedy here | ||
| // The total number of unmatched opening brackets at the end will tell us how many swaps are necessary to balance the string | ||
| // so, we keep track the number of unmatched closing brackets. | ||
| // Each swap can fix two unmatched brackets, so the minimum number of swaps required is (unmatched+1)/2 | ||
| private static void type1() { | ||
| String s = "]][][["; | ||
| int ans = minSwaps3(s); | ||
| System.out.println(ans); | ||
| } | ||
|
|
||
| public static int minSwaps3(String s) { | ||
| int imbalance = 0; // This variable tracks the number of unmatched closing brackets | ||
| int openBrackets = 0; // This variable tracks the number of unmatched opening brackets | ||
| // Iterate through each character in the string | ||
| for (char c : s.toCharArray()) { | ||
| if (c == '[') { | ||
| openBrackets++; // Increment for an opening bracket | ||
| } else { // c == ']' | ||
| if (openBrackets > 0) { | ||
| openBrackets--; // Match with an opening bracket | ||
| } else { | ||
| imbalance++; // Unmatched closing bracket | ||
| } | ||
| } | ||
| } | ||
| // Each swap can fix two imbalances, hence divide by 2 | ||
| return (imbalance + 1) / 2; | ||
| } | ||
|
|
||
|
|
||
| } |
Oops, something went wrong.