Merge pull request #109 from jsca-kwok/jk-richest-customer

Finding richest customer wealth: brute force and hash table approaches

DIRECTORY.md

@@ -14,6 +14,7 @@
     * [Get Products Of All Other Elements](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/get_products_of_all_other_elements.rb)
     * [Jewels And Stones](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/jewels_and_stones.rb)
     * [Remove Elements](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/remove_elements.rb)
+    * [Richest Customer Wealth](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/richest_customer.rb)
     * [Single Number](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/single_number.rb)
     * [Sort Squares Of An Array](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/sort_squares_of_an_array.rb)
     * [Two Sum](https://github.com/TheAlgorithms/Ruby/blob/master/data_structures/arrays/two_sum.rb)

data_structures/arrays/richest_customer_wealth.rb

@@ -0,0 +1,56 @@
+# Challenge name: Richest Customer Wealth
+#
+# You are given an m x n integer grid accounts where accounts[i][j]
+# is the amount of money the i​​​​​​​​​​​th​​​​ customer has in the j​​​​​​​​​​​th​​​​ bank.
+#
+# Return the wealth that the richest customer has.
+# A customer's wealth is the amount of money they have in all
+# their bank accounts. The richest customer is the customer that
+# has the maximum wealth.
+#
+# Example 1:
+# Input: accounts = [[1,2,3],[3,2,1]]
+# Output: 6
+# Explanation:
+# 1st customer has wealth = 1 + 2 + 3 = 6
+# 2nd customer has wealth = 3 + 2 + 1 = 6
+# Both customers are considered the richest with a wealth of 6
+# each, so return 6.
+#
+# Example 2:
+# Input: accounts = [[1,5],[7,3],[3,5]]
+# Output: 10
+# Explanation:
+# 1st customer has wealth = 6
+# 2nd customer has wealth = 10
+# 3rd customer has wealth = 8
+# The 2nd customer is the richest with a wealth of 10.
+#
+# Example 3:
+# Input: accounts = [[2,8,7],[7,1,3],[1,9,5]]
+# Output: 17
+
+#
+# Approach: Brute Force
+#
+# Time Complexity: O(n)
+#
+def find_richest_customer_wealth(accounts)
+  summed_accounts = []
+  accounts.each do |customer|
+    summed = 0
+    customer.each do |account|
+      summed += account
+    end
+    summed_accounts.push(summed)
+  end
+
+  summed_accounts.sort.pop()
+end
+
+puts find_richest_customer_wealth([[1,2,3],[3,2,1]])
+# => 6
+puts find_richest_customer_wealth([[1,5],[7,3],[3,5]])
+# => 10
+puts find_richest_customer_wealth([[2,8,7],[7,1,3],[1,9,5]])
+# => 17

data_structures/hash_table/richest_customer_wealth.rb

@@ -0,0 +1,59 @@
+# Challenge name: Richest Customer Wealth
+#
+# You are given an m x n integer grid accounts where accounts[i][j]
+# is the amount of money the i​​​​​​​​​​​th​​​​ customer has in the j​​​​​​​​​​​th​​​​ bank.
+#
+# Return the wealth that the richest customer has.
+# A customer's wealth is the amount of money they have in all
+# their bank accounts. The richest customer is the customer that
+# has the maximum wealth.
+#
+# Example 1:
+# Input: accounts = [[1,2,3],[3,2,1]]
+# Output: 6
+# Explanation:
+# 1st customer has wealth = 1 + 2 + 3 = 6
+# 2nd customer has wealth = 3 + 2 + 1 = 6
+# Both customers are considered the richest with a wealth of 6
+# each, so return 6.
+#
+# Example 2:
+# Input: accounts = [[1,5],[7,3],[3,5]]
+# Output: 10
+# Explanation:
+# 1st customer has wealth = 6
+# 2nd customer has wealth = 10
+# 3rd customer has wealth = 8
+# The 2nd customer is the richest with a wealth of 10.
+#
+# Example 3:
+# Input: accounts = [[2,8,7],[7,1,3],[1,9,5]]
+# Output: 17
+
+#
+# Approach: Hash
+#
+# Time Complexity: O(n)
+#
+def find_richest_customer_wealth(accounts)
+  result_hash = {}
+  accounts.each_with_index do |customer, i|
+    result_hash[i] = customer.sum
+  end
+
+  highest_value = 0
+  result_hash.each do |k, v|
+    if v > highest_value
+      highest_value = v
+    end
+  end
+
+  highest_value
+end
+
+puts find_richest_customer_wealth([[1,2,3],[3,2,1]])
+# => 6
+puts find_richest_customer_wealth([[1,5],[7,3],[3,5]])
+# => 10
+puts find_richest_customer_wealth([[2,8,7],[7,1,3],[1,9,5]])
+# => 17