Skip to content

Complete Design-1 #2628

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
PrakarshKamal wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Complete Design-1 #2628

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
38 changes: 38 additions & 0 deletions MinStack.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,38 @@
// O(1) time complexity for all operations
// O(n) space complexity

import java.util.Stack;

class MinStack {
Stack<Integer> minStack;
int min;

public MinStack() {
minStack = new Stack<>();
min = Integer.MAX_VALUE;
}

public void push(int val) {
if (val <= min) {
minStack.push(min); // push min
min = val;
}
minStack.push(val); // push val as it tracks curr min
}

public void pop() {
int popped = minStack.pop();
if (popped == min) {
min = minStack.pop();
}
}

public int top() {
return minStack.peek();
}

public int getMin() {
return min;
}
}

54 changes: 54 additions & 0 deletions MyHashSet.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,54 @@
// O(1) time, O(1) space

class MyHashSet {

boolean[][] storage;
int primaryBuckets;
int secondaryBuckets;

public MyHashSet() {
primaryBuckets = 1000;
secondaryBuckets = 1000;
storage = new boolean[primaryBuckets][];
}

private int getPrimaryHash(int key) {
return key % primaryBuckets;
}

private int getSecondaryHash(int key) {
return key / secondaryBuckets;
}

public void add(int key) {
int primaryHash = getPrimaryHash(key);
if (storage[primaryHash] == null) {
if (primaryHash == 0) {
storage[primaryHash] = new boolean[secondaryBuckets + 1];
}
else {
storage[primaryHash] = new boolean[secondaryBuckets];
}
}
int secondaryHash = getSecondaryHash(key);
storage[primaryHash][secondaryHash] = true;
}

public void remove(int key) {
int primaryHash = getPrimaryHash(key);
if (storage[primaryHash] == null) {
return;
}
int secondaryHash = getSecondaryHash(key);
storage[primaryHash][secondaryHash] = false;
}

public boolean contains(int key) {
int primaryHash = getPrimaryHash(key);
if (storage[primaryHash] == null) {
return false;
}
int secondaryHash = getSecondaryHash(key);
return storage[primaryHash][secondaryHash];
}
}