n piles of coins on a table. Each pile consists of a positive number of coins of assorted denominations.
In one move, you can choose any coin on top of any pile, remove it, and add it to your wallet.
Given a list
piles[i] is a list of integers denoting the composition of the
ith pile from top to bottom, and a positive integer
k, return the maximum total value of coins you can have in your wallet if you choose exactly
k coins optimally.
Input: piles = [[1,100,3],[7,8,9]], k = 2 Output: 101 Explanation: The above diagram shows the different ways we can choose k coins. The maximum total we can obtain is 101.
Input: piles = [,,,,,,[1,1,1,1,1,1,700]], k = 7 Output: 706 Explanation: The maximum total can be obtained if we choose all coins from the last pile.
n == piles.length
1 <= n <= 1000
1 <= piles[i][j] <= 105
1 <= k <= sum(piles[i].length) <= 2000