|
| 1 | +package com.interview.array; |
| 2 | + |
| 3 | +import java.util.Arrays; |
| 4 | +import java.util.Deque; |
| 5 | +import java.util.LinkedList; |
| 6 | +import java.util.List; |
| 7 | + |
| 8 | +/** |
| 9 | + *https://leetcode.com/problems/maximum-sum-of-3-non-overlapping-subarrays/description/ |
| 10 | + */ |
| 11 | +public class MaximumSumThreeNonOverlappingSubarray { |
| 12 | + |
| 13 | + public int[] maxSumOfThreeSubarrays(int[] nums, int k) { |
| 14 | + int sum = 0; |
| 15 | + int[] sumArray = new int[nums.length - k + 1]; |
| 16 | + for (int i = 0; i < nums.length; i++) { |
| 17 | + if (i < k) { |
| 18 | + sum += nums[i]; |
| 19 | + } else { |
| 20 | + sumArray[i - k] = sum; |
| 21 | + sum += nums[i]; |
| 22 | + sum -= nums[i - k]; |
| 23 | + } |
| 24 | + } |
| 25 | + sumArray[sumArray.length - 1] = sum; |
| 26 | + |
| 27 | + int[][] dp = new int[4][sumArray.length + 1]; |
| 28 | + |
| 29 | + for (int i = 1; i <= 3; i++) { |
| 30 | + for (int j = 1; j <= sumArray.length; j++) { |
| 31 | + if (j >= k) { |
| 32 | + if (dp[i][j - 1] >= sumArray[j - 1] + dp[i - 1][j - k]) { |
| 33 | + dp[i][j] = dp[i][j - 1]; |
| 34 | + } else { |
| 35 | + dp[i][j] = sumArray[j - 1] + dp[i - 1][j - k]; |
| 36 | + } |
| 37 | + } else { |
| 38 | + if (dp[i][j - 1] >= sumArray[j - 1]) { |
| 39 | + dp[i][j] = dp[i][j - 1]; |
| 40 | + } else { |
| 41 | + dp[i][j] = sumArray[j - 1]; |
| 42 | + } |
| 43 | + } |
| 44 | + } |
| 45 | + } |
| 46 | + int[] output = new int[3]; |
| 47 | + int j = dp[0].length - 1; |
| 48 | + for (int i = 3; i > 0;) { |
| 49 | + if (dp[i][j] == dp[i][j - 1]) { |
| 50 | + j--; |
| 51 | + } else { |
| 52 | + output[i - 1] = j - 1; |
| 53 | + i--; |
| 54 | + j = j - k; |
| 55 | + } |
| 56 | + } |
| 57 | + return output; |
| 58 | + } |
| 59 | + |
| 60 | + public static void main(String[] args) { |
| 61 | + MaximumSumThreeNonOverlappingSubarray mss = new MaximumSumThreeNonOverlappingSubarray(); |
| 62 | + int[] input = {3, 2, 2, 1, 1, 0, 5}; |
| 63 | + int[] input1 = {1, 2, 1, 2, 6, 7, 5, 1}; |
| 64 | + int[] output = mss.maxSumOfThreeSubarrays(input1, 2); |
| 65 | + for (int i : output) { |
| 66 | + System.out.println(i); |
| 67 | + } |
| 68 | + } |
| 69 | +} |
0 commit comments