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Java-based LeetCode algorithm problem solutions, regularly updated
package g0901_1000.s0992_subarrays_with_k_different_integers;
// #Hard #Array #Hash_Table #Counting #Sliding_Window
// #2022_03_31_Time_4_ms_(99.36%)_Space_46.2_MB_(86.91%)
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;
}
}