# ---
# title: 473. Matchsticks to Square
# id: problem473
# author: Tian Jun
# date: 2020-10-31
# difficulty: Medium
# categories: Depth-first Search
# link: <https://leetcode.com/problems/matchsticks-to-square/description/>
# hidden: true
# ---
# 
# Remember the story of Little Match Girl? By now, you know exactly what
# matchsticks the little match girl has, please find out a way you can make one
# square by using up all those matchsticks. You should not break any stick, but
# you can link them up, and each matchstick must be used **exactly** one time.
# 
# Your input will be several matchsticks the girl has, represented with their
# stick length. Your output will either be true or false, to represent whether
# you could make one square using all the matchsticks the little match girl has.
# 
# **Example 1:**  
# 
#     
#     
#     Input: [1,1,2,2,2]
#     Output: true
#     
#     Explanation: You can form a square with length 2, one side of the square came two sticks with length 1.
#     
# 
# **Example 2:**  
# 
#     
#     
#     Input: [3,3,3,3,4]
#     Output: false
#     
#     Explanation: You cannot find a way to form a square with all the matchsticks.
#     
# 
# **Note:**  
# 
#   1. The length sum of the given matchsticks is in the range of `0` to `10^9`. 
#   2. The length of the given matchstick array will not exceed `15`.
# 
# 
## @lc code=start
using LeetCode

## add your code here:
## @lc code=end
