bhaveshmunot1

/* Watch video explanation here: https://youtu.be/MmhfOzYMYPk */
class Solution {
    vector<vector<int>> ans;   // Stores the final answer.
    
    /* Skip the duplicates. */
    int increment(vector<int>& nums, int cur) {
        int n = nums.size();
        int j=cur+1;
        while (j < n && nums[j] == nums[cur]) {
            j++;

bhaveshmunot1

// Video Explanation: https://youtu.be/i2y6LTIz_WU
class Solution {
public:
    vector<int> twoSum(vector<int>& numbers, int target) { 
        int n = numbers.size(); 
        int left = 0;     // Smallest number.
        int right = n-1;  // Largest number.
        while (numbers[left] + numbers[right] != target) {
            if (numbers[left] + numbers[right] < target) { // Current sum is not sufficient
                                                           // to reach the target.

bhaveshmunot1

class Solution {
public:
    int climbStairs(int n) {
        vector<int> dp(n+1) = {0, 1, 2}; // Stores number of ways in which
                                         // i-th step can be reached, at
                                         // location dp[i].
        
        for (int i=3; i<=n; i++) {       // For each step - (bottom to top)
            dp[i] = dp[i-1] + dp[i-2];   // All the ways in which (i-1)-th 
                                         // step can be reached AND all the

bhaveshmunot1

class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        unordered_map<int, int> m;     // To store the integer and its index.
        int n = nums.size();           // Total integers.
        for (int i=0; i<n; i++) {      // For each integer, say K -
            if (m.find(target-nums[i]) != m.end()) { // Check if (target - K) exists.
                return {i, m[target-nums[i]]};       // Yay, found the answer.
            }
            m[nums[i]] = i;            // Save the K in the map with it's index.

bhaveshmunot1

class Solution {
   inline char toggle(char c) {
     return c == '0' ?  '1' : '0';
   }
public:
    int minFlips(string target) {
        int n = target.size();           // Total bulbs.
        int flips = 0;                   // Final answer.
        char status = '0';               // This stores the status of bulbs that
                                         // are ahead of current index `i`.

bhaveshmunot1

class Solution {
public:
    int getLastMoment(int n, vector<int>& left, vector<int>& right) {
        // The one that is farthest from the left end, but desires to go in the left
        // direction, will be the last one to go off of the plank from the left side.
        int maxLeft = left.empty() ? 0 : *max_element(left.begin(), left.end());
        
        // Similarly,
        // The one that is farthest from the right end, but desires to go in the right
        // direction, will be the last one to go off of the plank from the right side.

bhaveshmunot1

class Solution {
public:
    unordered_map<string, int> nameSuffix; // Folder name -> Next available value 
                                        // for the suffix.
    
    string addSuffix(string name) {
        string newName = "";
        do {
            newName = name + "(" + to_string(nameSuffix[name]) + ")"; // Generate a name.
            nameSuffix[name]++;                    // Increase the count by one

bhaveshmunot1

class Solution {
public:
    vector<int> avoidFlood(vector<int>& rains) {
        vector<int> ans; // Store the final answer here.
        int n = rains.size(); 
        unordered_map<int, int> fulllakes; // Lake number -> day on which it became full.
        set<int> drydays; // Set of available days that can be used for drying a full lake.
        for (int i=0; i<n; i++) {  // For each day - 
            if (rains[i] == 0) {  // No rain on this day.
                drydays.insert(i); // This day can be used as a day to dry some lake.

bhaveshmunot1

class Solution {
    const int mod = (1e9)+7; // As the question expects.
    
    int getMax(int length, vector<int> &cuts) {
        sort(cuts.begin(), cuts.end()); // Sort so that we will easily get the thickness
                                        // of each piece after cutting it.
        int n = cuts.size();
        int maxCut = max(length-cuts[n-1], // Thickness of the last piece.
                         cuts[0]);         // Thickness of the first piece.
        for (int i=1; i<n; i++) { // For each cut -

bhaveshmunot1

class Solution {
    unordered_map<char, int> frequency; // Stores how many times each sound has occured. 
                                        // Sounds are c, r, o, a, k. 
    /*
     *  At any time, for a sequence to be valid, number of 'c' must not be less than 'r'.
     *  Similarly, #'r' shouldn't  less than #'o', and so on.
     */
    bool isStateValid() {
         return (frequency['c'] >= frequency['r']) &&
                (frequency['r'] >= frequency['o']) &&