g0901_1000.s0992_subarrays_with_k_different_integers.Solution Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of leetcode-in-java Show documentation

Java-based LeetCode algorithm problem solutions, regularly updated

There is a newer version: 1.37

package g0901_1000.s0992_subarrays_with_k_different_integers;

// #Hard #Array #Hash_Table #Sliding_Window #Counting

public class Solution {
    public int subarraysWithKDistinct(int[] nums, int k) {
        int res = 0;
        int prefix = 0;
        int[] cnt = new int[nums.length + 1];
        int i = 0;
        int j = 0;
        int uniqueCount = 0;
        while (i < nums.length) {
            if (cnt[nums[i]]++ == 0) {
                uniqueCount++;
            }
            if (uniqueCount > k) {
                --cnt[nums[j++]];
                prefix = 0;
                uniqueCount--;
            }
            while (cnt[nums[j]] > 1) {
                ++prefix;
                --cnt[nums[j++]];
            }
            if (uniqueCount == k) {
                res += prefix + 1;
            }
            i++;
        }
        return res;
    }
}