Leetcode 2369 Check if There is a Valid Partition For The Array Solution in Java | Hindi Coding Community

 

You are given a 0-indexed integer array nums. You have to partition the array into one or more contiguous subarrays.

We call a partition of the array valid if each of the obtained subarrays satisfies one of the following conditions:

1. The subarray consists of exactly 2 equal elements. For example, the subarray [2,2] is good.
2. The subarray consists of exactly 3 equal elements. For example, the subarray [4,4,4] is good.
3. The subarray consists of exactly 3 consecutive increasing elements, that is, the difference between adjacent elements is 1. For example, the subarray [3,4,5] is good, but the subarray [1,3,5] is not.

Return true if the array has at least one valid partition. Otherwise, return false.

 

Example 1:

Input: nums = [4,4,4,5,6]
Output: true
Explanation: The array can be partitioned into the subarrays [4,4] and [4,5,6].
This partition is valid, so we return true.

Example 2:

Input: nums = [1,1,1,2]
Output: false
Explanation: There is no valid partition for this array.

 

Constraints:

• 2 <= nums.length <= 105
• 1 <= nums[i] <= 106

Java Code :

public boolean validPartition(int[] n) {

boolean[] dp = {true, false, n[0] == n[1], false};

for (int i = 2; i < n.length; ++i) {

boolean two = n[i] == n[i - 1];

boolean three = (two && n[i] == n[i - 2]) || (n[i] - 1 == n[i - 1] && n[i] - 2 == n[i - 2]);

dp[(i + 1) % 4] = (two && dp[(i - 1) % 4]) || (three && dp[(i - 2) % 4]);

}

return dp[n.length % 4];

}