Leetcode Problem 2780. Minimum Index of a Valid Split
2780. Minimum Index of a Valid Split
Leetcode Solutions
Finding the Minimum Index for a Valid Split with Dominant Element
Initialize a frequency map to count the occurrences of each element in the array.
Identify the dominant element by finding the element with a frequency greater than half the size of the array.
Initialize two variables to keep track of the frequency of the dominant element in the left and right subarrays.
Iterate through the array from left to right, updating the frequency of the dominant element in the left subarray.
At each index, calculate the frequency of the dominant element in the right subarray by subtracting the left frequency from the total frequency of the dominant element.
Check if the current index provides a valid split by ensuring the dominant element is dominant in both subarrays.
If a valid split is found, return the current index. If no valid split is found by the end of the iteration, return -1.
Alternative Approach: Prefix and Suffix Frequency Count