474. Ones and Zeroes
https://leetcode.com/problems/ones-and-zeroes/description/
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.
Constraints:
1 <= strs.length <= 600
1 <= strs[i].length <= 100
strs[i]
consists only of digits'0'
and'1'
.1 <= m, n <= 100
----
Intuition
At each position, either include the string or skip
dfs with branching factor of 2
to include make sure m, n remaining are valid
to skip, don't change m, n
memoize - 3 changing variables m, n, index
terminate recursion when no more moves are possible ie. index == length || m + n == 0
----