JyotinderSingh

class Solution
{
public:
    vector<int> spiralOrder(vector<vector<int>> &matrix)
    {
        vector<int> res;

        if (!matrix.size())
            return res;
        int rows = matrix.size(), cols = matrix[0].size();

JyotinderSingh

class Solution {
public:
    ListNode* reverseBetween(ListNode* head, int start, int end) {
        if(!head || start == end) return head;
        
        ListNode dummyHead(INT_MIN);
        dummyHead.next = head;
        
        auto* nodeBeforeReversedSublist = &dummyHead;
        int pos = 1;

JyotinderSingh

class Solution {
public:
    int islandPerimeter(vector<vector<int>>& grid) {
        int perimeter = 0;
        for(int i = 0; i < grid.size(); ++i) {
            for(int j = 0; j < grid[0].size(); ++j) {
                if(grid[i][j]) {
                    perimeter += (i == 0 || grid[i - 1][j] == 0) + (i == grid.size() - 1 || grid[i + 1][j] == 0)  + (j == 0 || grid[i][j - 1] == 0) + (j == grid[0].size() - 1 || grid[i][j + 1] == 0);
                }
            }

JyotinderSingh

class Solution
{
public:
    int countLargestGroup(int n)
    {
        // vector to maintain sizes of each of the groups
        // note that max sum of digits can be for 9999 (9 + 9 + 9 + 9 = 36)
        vector<int> count(37);
        int max_size = 0;
        int res = 0;

JyotinderSingh

class Solution {
public:
    vector<int> plusOne(vector<int>& digits) {
        digits.back()++;
        for(int i = digits.size() - 1; i > 0 && digits[i] == 10; --i) {
            digits[i] = 0;
            digits[i - 1]++;
        }
        
        if(digits[0] == 10) {

JyotinderSingh

class Solution {
public:
    int numSubseq(vector<int>& nums, int target) {
        const int MOD = 1000000007;
        vector<int> exponents(nums.size(), 1);
        // calculate all the possible expoenents you might need and save them beforehand
        for(int i = 1; i < exponents.size(); ++i) {
            exponents[i]  = (2 * exponents[i - 1]) % MOD;
        }
        

JyotinderSingh

class Solution {
public:
    int arrangeCoins(int n) {
        long n_long = (long) n;
        long left = 1, right = n_long;
        
        while(left <= right) {
            long mid = left + (right - left) / 2; // (left + right) / 2
            
            if(mid * (mid + 1) / 2 <= n_long) {

JyotinderSingh

class Solution
{
public:
    bool exist(vector<vector<char>> &board, string word)
    {

        for (int i = 0; i < board.size(); ++i)
        {
            for (int j = 0; j < board[0].size(); ++j)

JyotinderSingh

class Solution {
public:
    int minDistance(string word1, string word2) {
        vector<vector<int>> dp(word2.size() + 1, vector<int> (word1.size() + 1));
        
        /*
        * Going downwards in the first column (for "" as the first string),
        * we're performing the insert operation
        * And the number of inserts to turn an empty string to a 
        * string with length L is L

JyotinderSingh

class Solution
{
public:
    vector<vector<int>> fourSum(vector<int> &nums, int target)
    {
        vector<vector<int>> res;
        if (nums.size() < 4)
        {
            return res;
        }