1985.KthLargestNumber.cs

// 1985. Find the Kth Largest Integer in the Array

// You are given an array of strings nums and an integer k. Each string in nums represents an integer without leading zeros.

// Return the string that represents the kth largest integer in nums.

// Note: Duplicate numbers should be counted distinctly. For example, if nums is ["1","2","2"], "2" is the first largest integer, "2" is the second-largest integer, and "1" is the third-largest integer.

 

// Example 1:

// Input: nums = ["3","6","7","10"], k = 4
// Output: "3"
// Explanation:
// The numbers in nums sorted in non-decreasing order are ["3","6","7","10"].
// The 4th largest integer in nums is "3".
// Example 2:

// Input: nums = ["2","21","12","1"], k = 3
// Output: "2"
// Explanation:
// The numbers in nums sorted in non-decreasing order are ["1","2","12","21"].
// The 3rd largest integer in nums is "2".
// Example 3:

// Input: nums = ["0","0"], k = 2
// Output: "0"
// Explanation:
// The numbers in nums sorted in non-decreasing order are ["0","0"].
// The 2nd largest integer in nums is "0".

public class Solution {
    public string KthLargestNumber(string[] nums, int k) {
        PriorityQueue<string,BigInteger> minHeap = 
            new PriorityQueue<string,BigInteger>();
        foreach(var item in nums){
            BigInteger num = BigInteger.Parse(item);
            minHeap.Enqueue(item,num);
            if(minHeap.Count > k)
                minHeap.Dequeue();
        }
        
        return minHeap.Dequeue();
    }
}