{leetcode}/problems/k-concatenation-maximum-sum/[LeetCode - K-Concatenation Maximum Sum^]
Given an integer array arr and an integer k, modify the array by repeating it k times.
For example, if arr = [1, 2] and k = 3 `then the modified array will be `[1, 2, 1, 2, 1, 2].
Return the maximum sub-array sum in the modified array. Note that the length of the sub-array can be 0 and its sum in that case is 0.
As the answer can be very large, return the answer modulo 10^9 + 7.
Example 1:
Input: arr = [1,2], k = 3 Output: 9
Example 2:
Input: arr = [1,-2,1], k = 5 Output: 2
Example 3:
Input: arr = [-1,-2], k = 7 Output: 0
Constraints:
-
1 ⇐ arr.length ⇐ 10^5 -
1 ⇐ k ⇐ 10^5 -
-10^4 ⇐ arr[i] ⇐ 10^4
link:{sourcedir}/_1191_KConcatenationMaximumSum.java[role=include]