# You are given an array of binary strings strs and two integers m and n. # # Return the size of the largest subset of strs such that there are at most m 0's and n 1's in the subset. # # A set x is a subset of a set y if all elements of x are also elements of y. # # Example 1: # # Input: strs = ["10","0001","111001","1","0"], m = 5, n = 3 # Output: 4 # Explanation: The largest subset with at most 5 0's and 3 1's is {"10", "0001", "1", "0"}, so the answer is 4. # Other valid but smaller subsets include {"0001", "1"} and {"10", "1", "0"}. # {"111001"} is an invalid subset because it contains 4 1's, greater than the maximum of 3. # # Example 2: # # Input: strs = ["10","0","1"], m = 1, n = 1 # Output: 2 # Explanation: The largest subset is {"0", "1"}, so the answer is 2. # # Approach #1 Dynamic Programming # # @param {String[]} strs # @param {Integer} m # @param {Integer} n # @return {Integer} def find_max_form(strs, m, n) dp = (m + 1).times.map { [0] * (n + 1) } strs.each do |str| zeros = str.count('0') ones = str.count('1') m.downto(zeros) do |i| n.downto(ones) do |j| dp[i][j] = [dp[i][j], dp[i - zeros][j - ones] + 1].max end end end dp[m][n] end strs = %w[10 0001 111001 1 0] m = 5 n = 3 puts find_max_form(strs, m, n) # Output: 4 strs = %w[10 0 1] m = 1 n = 1 puts find_max_form(strs, m, n) # Output: 2