LeetCode 2899: Last Visited Integers
Problem Description
Explanation
The problem requires finding the last visited positive integer for each occurrence of -1 in the given array. We can achieve this by maintaining two arrays, seen and ans. We iterate through the nums array, updating seen with positive integers and handling -1 occurrences to calculate the last visited integer. The algorithm involves keeping track of consecutive -1 occurrences and accessing the appropriate element from the seen array.
- Time complexity: O(n) where n is the length of the input array
nums. - Space complexity: O(n) for the
seenandansarrays.
Solutions
class Solution {
public int[] findLastVisited(int[] nums) {
int n = nums.length;
int[] seen = new int[n];
int[] ans = new int[n];
int idx = 0;
for (int num : nums) {
if (num != -1) {
seen[idx++] = num;
} else {
int k = 1;
while (k <= idx && seen[idx - k] == -1) {
k++;
}
ans[idx] = k <= idx ? seen[idx - k] : -1;
idx++;
}
}
return Arrays.copyOf(ans, idx);
}
}Loading editor...