janehwzn

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {

janehwzn

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {

janehwzn

class Solution {
public:
    int findMinArrowShots(vector<pair<int, int>>& points) {
        if (points.empty()) return 0;
        int res = 0;
        int begin = 0, count = 1;
        std::sort(points.begin(), points.end(), sort_pred());
        
        while(!points.empty()) {
            while(begin+count < points.size() && points[begin].second >= points[begin+count].first) {

janehwzn

class Node {
  int val;
  int index_x, index_y;

public:
  Node (int _val, int _index_x, int _index_y) {
    val = _val;
    index_x = _index_x;
    index_y = _index_y;
  }

janehwzn

/**
 * Definition for singly-linked list with a random pointer.
 * struct RandomListNode {
 *     int label;
 *     RandomListNode *next, *random;
 *     RandomListNode(int x) : label(x), next(NULL), random(NULL) {}
 * };
 */
class Solution {
public:

janehwzn

var reverseWords = function(str) {
    return str.split(' ').reverse().filter(Boolean).join(' ');
};

janehwzn

class Solution {
public:
    int trailingZeroes(int n) {
        //because 2 is always more than 5, so just count 5.
        // floor(n/5) + floor(n/25) + floor(n/125) .... until n< 5 ^ i
        if (n<0) return -1;
        int res = 0;
        for (long i = 5; n>=i; i *= 5) {
            res += n/i;
        }

janehwzn

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:

janehwzn

class Solution {
public:
    bool isAnagram(string s, string t) {
          sort(s.begin(), s.end());
          sort(t.begin(), t.end());
          return s==t;
    }
};

janehwzn

class Solution {
public:
    bool isAnagram(string s, string t) {
         if (s.size() != t.size()) return false;
         unordered_map<char, int> a, b;
         for (int i = 0; i<s.size(); i++) {
             if (a.count(s[i])) {
                 a[s[i]]++;
             } else {
                 a[s[i]] = 1;