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Merged
merged 1 commit into from
Mar 9, 2025
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Improved task 373 #1936

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2 changes: 1 addition & 1 deletion README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -1698,7 +1698,7 @@ implementation 'com.github.javadev:leetcode-in-java:1.41'
|-|-|-|-|-|-
| 0215 |[Kth Largest Element in an Array](src/main/java/g0201_0300/s0215_kth_largest_element_in_an_array/Solution.java)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting, Heap_Priority_Queue, Divide_and_Conquer, Quickselect, Big_O_Time_O(n\*log(n))_Space_O(log(n)) | 5 | 70.82
| 0502 |[IPO](src/main/java/g0501_0600/s0502_ipo/Solution.java)| Hard | Array, Sorting, Greedy, Heap_Priority_Queue | 64 | 97.22
| 0373 |[Find K Pairs with Smallest Sums](src/main/java/g0301_0400/s0373_find_k_pairs_with_smallest_sums/Solution.java)| Medium | Array, Heap_Priority_Queue | 0 | 100.00
| 0373 |[Find K Pairs with Smallest Sums](src/main/java/g0301_0400/s0373_find_k_pairs_with_smallest_sums/Solution.java)| Medium | Array, Heap_Priority_Queue | 27 | 90.23
| 0295 |[Find Median from Data Stream](src/main/java/g0201_0300/s0295_find_median_from_data_stream/MedianFinder.java)| Hard | Top_100_Liked_Questions, Sorting, Two_Pointers, Design, Heap_Priority_Queue, Data_Stream, Big_O_Time_O(n\*log_n)_Space_O(n) | 83 | 99.56

#### Top Interview 150 Bit Manipulation
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122 changes: 30 additions & 92 deletions src/main/java/g0301_0400/s0373_find_k_pairs_with_smallest_sums/Solution.java
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@@ -1,104 +1,42 @@
package g0301_0400.s0373_find_k_pairs_with_smallest_sums;

// #Medium #Array #Heap_Priority_Queue #Top_Interview_150_Heap
// #2025_03_09_Time_0_ms_(100.00%)_Space_57.66_MB_(90.88%)
// #2025_03_09_Time_27_ms_(90.23%)_Space_58.22_MB_(77.32%)

import java.util.AbstractList;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.PriorityQueue;

public class Solution {
public List<List<Integer>> kSmallestPairs(int[] nums1, int[] nums2, int k) {
return new AbstractList<List<Integer>>() {
private List<List<Integer>> pairs;

@Override
public List<Integer> get(int index) {
init();
return pairs.get(index);
}

@Override
public int size() {
init();
return pairs.size();
}

private void load() {
int n = nums1.length;
int m = nums2.length;
int left = nums1[0] + nums2[0];
int right = nums1[n - 1] + nums2[m - 1];
int middle;

while (left <= right) {
middle = (left + right) / 2;
long count = getCount(nums1, nums2, middle, k);
if (count < k) {
left = middle + 1;
} else if (count > k) {
right = middle - 1;
} else {
left = middle;
break;
}
}
getPairs(nums1, nums2, left, k);
}

private long getCount(int[] nums1, int[] nums2, int goal, int k) {
int prevRight = nums2.length - 1;
int count = 0;

for (int i = 0; i < nums1.length && nums1[i] + nums2[0] <= goal; i++) {
int left = 0;
int right = prevRight;
int position = -1;
while (left <= right) {
int middle = (right + left) / 2;
int sum = nums1[i] + nums2[middle];
if (sum <= goal) {
position = middle;
left = middle + 1;
} else {
right = middle - 1;
}
}
if (position >= 0) {
count += position + 1;
prevRight = position;
}
if (count > k) {
return count;
}
}
return count;
}

private void getPairs(int[] nums1, int[] nums2, int sum, int k) {
pairs = new ArrayList<>();
for (int item : nums1) {
for (int j = 0; j < nums2.length && item + nums2[j] < sum; j++) {
pairs.add(Arrays.asList(item, nums2[j]));
}
}
for (int value : nums1) {
for (int j = 0;
j < nums2.length && value + nums2[j] <= sum && pairs.size() < k;
j++) {
if (value + nums2[j] == sum) {
pairs.add(Arrays.asList(value, nums2[j]));
}
}
}
}
private static class Node {
long sum;
List<Integer> al;
int index;

Node(int index, int num1, int num2) {
this.sum = (long) num1 + (long) num2;
this.al = new ArrayList<>();
this.al.add(num1);
this.al.add(num2);
this.index = index;
}
}

public void init() {
if (null == pairs) {
load();
}
public List<List<Integer>> kSmallestPairs(int[] nums1, int[] nums2, int k) {
PriorityQueue<Node> queue = new PriorityQueue<>((a, b) -> a.sum < b.sum ? -1 : 1);
List<List<Integer>> res = new ArrayList<>();
for (int i = 0; i < nums1.length && i < k; i++) {
queue.add(new Node(0, nums1[i], nums2[0]));
}
for (int i = 1; i <= k && !queue.isEmpty(); i++) {
Node cur = queue.poll();
res.add(cur.al);
int next = cur.index;
int lastNum1 = cur.al.get(0);
if (next + 1 < nums2.length) {
queue.add(new Node(next + 1, lastNum1, nums2[next + 1]));
}
};
}
return res;
}
}