+ problem 373

Author: fruit-in

Problemset/0373-Find K Pairs with Smallest Sums/README.md

@@ -0,0 +1,55 @@
+# 373. Find K Pairs with Smallest Sums
+You are given two integer arrays `nums1` and `nums2` sorted in **non-decreasing order** and an integer `k`.
+
+Define a pair `(u, v)` which consists of one element from the first array and one element from the second array.
+
+Return *the* `k` *pairs* <code>(u<sub>1</sub>, v<sub>1</sub>), (u<sub>2</sub>, v<sub>2</sub>), ..., (u<sub>k</sub>, v<sub>k</sub>)</code> *with the smallest sums*.
+
+#### Example 1:
+<pre>
+<strong>Input:</strong> nums1 = [1,7,11], nums2 = [2,4,6], k = 3
+<strong>Output:</strong> [[1,2],[1,4],[1,6]]
+<strong>Explanation:</strong> The first 3 pairs are returned from the sequence: [1,2],[1,4],[1,6],[7,2],[7,4],[11,2],[7,6],[11,4],[11,6]
+</pre>
+
+#### Example 2:
+<pre>
+<strong>Input:</strong> nums1 = [1,1,2], nums2 = [1,2,3], k = 2
+<strong>Output:</strong> [[1,1],[1,1]]
+<strong>Explanation:</strong> The first 2 pairs are returned from the sequence: [1,1],[1,1],[1,2],[2,1],[1,2],[2,2],[1,3],[1,3],[2,3]
+</pre>
+
+#### Constraints:
+* <code>1 <= nums1.length, nums2.length <= 10<sup>5</sup></code>
+* <code>-10<sup>9</sup> <= nums1[i], nums2[i] <= 10<sup>9</sup></code>
+* `nums1` and `nums2` both are sorted in **non-decreasing order**.
+* <code>1 <= k <= 10<sup>4</sup></code>
+* `k <= nums1.length * nums2.length`
+
+## Solutions (Rust)
+
+### 1. Solution
+```Rust
+use std::cmp::Reverse;
+use std::collections::BinaryHeap;
+
+impl Solution {
+    pub fn k_smallest_pairs(nums1: Vec<i32>, nums2: Vec<i32>, k: i32) -> Vec<Vec<i32>> {
+        let mut heap = (0..nums1.len().min(k as usize))
+            .map(|i| (Reverse(nums1[i] + nums2[0]), i, 0))
+            .collect::<BinaryHeap<_>>();
+        let mut ret = vec![];
+
+        for _ in 0..k {
+            let (_, i, j) = heap.pop().unwrap();
+
+            if j + 1 < nums2.len() {
+                heap.push((Reverse(nums1[i] + nums2[j + 1]), i, j + 1));
+            }
+            ret.push(vec![nums1[i], nums2[j]]);
+        }
+
+        ret
+    }
+}
+```

Problemset/0373-Find K Pairs with Smallest Sums/README_CN.md

@@ -0,0 +1,57 @@
+# 373. 查找和最小的 K 对数字
+给定两个以 **非递减顺序排列** 的整数数组 `nums1` 和 `nums2` , 以及一个整数 `k` 。
+
+定义一对值 `(u,v)`，其中第一个元素来自 `nums1`，第二个元素来自 `nums2` 。
+
+请找到和最小的 `k` 个数对 <code>(u<sub>1</sub>,v<sub>1</sub>)</code>,  <code>(u<sub>2</sub>,v<sub>2</sub>)</code>  ...  <code>(u<sub>k</sub>,v<sub>k</sub>)</code> 。
+
+#### 示例 1:
+<pre>
+<strong>输入:</strong> nums1 = [1,7,11], nums2 = [2,4,6], k = 3
+<strong>输出:</strong> [[1,2],[1,4],[1,6]]
+<strong>解释:</strong> 返回序列中的前 3 对数：
+     [1,2],[1,4],[1,6],[7,2],[7,4],[11,2],[7,6],[11,4],[11,6]
+</pre>
+
+#### 示例 2:
+<pre>
+<strong>输入:</strong> nums1 = [1,1,2], nums2 = [1,2,3], k = 2
+<strong>输出:</strong> [[1,1],[1,1]]
+<strong>解释:</strong> 返回序列中的前 2 对数：
+     [1,1],[1,1],[1,2],[2,1],[1,2],[2,2],[1,3],[1,3],[2,3]
+</pre>
+
+#### 提示:
+* <code>1 <= nums1.length, nums2.length <= 10<sup>5</sup></code>
+* <code>-10<sup>9</sup> <= nums1[i], nums2[i] <= 10<sup>9</sup></code>
+* `nums1` 和 `nums2` 均为 **升序排列**
+* <code>1 <= k <= 10<sup>4</sup></code>
+* `k <= nums1.length * nums2.length`
+
+## 题解 (Rust)
+
+### 1. 题解
+```Rust
+use std::cmp::Reverse;
+use std::collections::BinaryHeap;
+
+impl Solution {
+    pub fn k_smallest_pairs(nums1: Vec<i32>, nums2: Vec<i32>, k: i32) -> Vec<Vec<i32>> {
+        let mut heap = (0..nums1.len().min(k as usize))
+            .map(|i| (Reverse(nums1[i] + nums2[0]), i, 0))
+            .collect::<BinaryHeap<_>>();
+        let mut ret = vec![];
+
+        for _ in 0..k {
+            let (_, i, j) = heap.pop().unwrap();
+
+            if j + 1 < nums2.len() {
+                heap.push((Reverse(nums1[i] + nums2[j + 1]), i, j + 1));
+            }
+            ret.push(vec![nums1[i], nums2[j]]);
+        }
+
+        ret
+    }
+}
+```

Problemset/0373-Find K Pairs with Smallest Sums/Solution.rs

@@ -0,0 +1,22 @@
+use std::cmp::Reverse;
+use std::collections::BinaryHeap;
+
+impl Solution {
+    pub fn k_smallest_pairs(nums1: Vec<i32>, nums2: Vec<i32>, k: i32) -> Vec<Vec<i32>> {
+        let mut heap = (0..nums1.len().min(k as usize))
+            .map(|i| (Reverse(nums1[i] + nums2[0]), i, 0))
+            .collect::<BinaryHeap<_>>();
+        let mut ret = vec![];
+
+        for _ in 0..k {
+            let (_, i, j) = heap.pop().unwrap();
+
+            if j + 1 < nums2.len() {
+                heap.push((Reverse(nums1[i] + nums2[j + 1]), i, j + 1));
+            }
+            ret.push(vec![nums1[i], nums2[j]]);
+        }
+
+        ret
+    }
+}

README.md

@@ -234,6 +234,7 @@
 [368][368l]  |[Largest Divisible Subset][368]                                                       |![rs]
 [371][371l]  |[Sum of Two Integers][371]                                                            |![rs]
 [372][372l]  |[Super Pow][372]                                                                      |![rs]
+[373][373l]  |[Find K Pairs with Smallest Sums][373]                                                |![rs]
 [374][374l]  |[Guess Number Higher or Lower][374]                                                   |![py]
 [380][380l]  |[Insert Delete GetRandom O(1)][380]                                                   |![rs]
 [382][382l]  |[Linked List Random Node][382]                                                        |![py]
@@ -1657,6 +1658,7 @@
 [368]:Problemset/0368-Largest%20Divisible%20Subset/README.md#368-largest-divisible-subset
 [371]:Problemset/0371-Sum%20of%20Two%20Integers/README.md#371-sum-of-two-integers
 [372]:Problemset/0372-Super%20Pow/README.md#372-super-pow
+[373]:Problemset/0373-Find%20K%20Pairs%20with%20Smallest%20Sums/README.md#373-find-k-pairs-with-smallest-sums
 [374]:Problemset/0374-Guess%20Number%20Higher%20or%20Lower/README.md#374-guess-number-higher-or-lower
 [380]:Problemset/0380-Insert%20Delete%20GetRandom%20O\(1\)/README.md#380-insert-delete-getrandom-o1
 [382]:Problemset/0382-Linked%20List%20Random%20Node/README.md#382-linked-list-random-node
@@ -3077,6 +3079,7 @@
 [368l]:https://leetcode.com/problems/largest-divisible-subset/
 [371l]:https://leetcode.com/problems/sum-of-two-integers/
 [372l]:https://leetcode.com/problems/super-pow/
+[373l]:https://leetcode.com/problems/find-k-pairs-with-smallest-sums/
 [374l]:https://leetcode.com/problems/guess-number-higher-or-lower/
 [380l]:https://leetcode.com/problems/insert-delete-getrandom-o1/
 [382l]:https://leetcode.com/problems/linked-list-random-node/

README_CN.md

@@ -234,6 +234,7 @@
 [368][368l]  |[最大整除子集][368]                                       |![rs]
 [371][371l]  |[两整数之和][371]                                         |![rs]
 [372][372l]  |[超级次方][372]                                           |![rs]
+[373][373l]  |[查找和最小的 K 对数字][373]                              |![rs]
 [374][374l]  |[猜数字大小][374]                                         |![py]
 [380][380l]  |[O(1) 时间插入、删除和获取随机元素][380]                  |![rs]
 [382][382l]  |[链表随机节点][382]                                       |![py]
@@ -1657,6 +1658,7 @@
 [368]:Problemset/0368-Largest%20Divisible%20Subset/README_CN.md#368-最大整除子集
 [371]:Problemset/0371-Sum%20of%20Two%20Integers/README_CN.md#371-两整数之和
 [372]:Problemset/0372-Super%20Pow/README_CN.md#372-超级次方
+[373]:Problemset/0373-Find%20K%20Pairs%20with%20Smallest%20Sums/README_CN.md#373-查找和最小的-k-对数字
 [374]:Problemset/0374-Guess%20Number%20Higher%20or%20Lower/README_CN.md#374-猜数字大小
 [380]:Problemset/0380-Insert%20Delete%20GetRandom%20O\(1\)/README_CN.md#380-o1-时间插入删除和获取随机元素
 [382]:Problemset/0382-Linked%20List%20Random%20Node/README_CN.md#382-链表随机节点
@@ -3077,6 +3079,7 @@
 [368l]:https://leetcode.cn/problems/largest-divisible-subset/
 [371l]:https://leetcode.cn/problems/sum-of-two-integers/
 [372l]:https://leetcode.cn/problems/super-pow/
+[373l]:https://leetcode.cn/problems/find-k-pairs-with-smallest-sums/
 [374l]:https://leetcode.cn/problems/guess-number-higher-or-lower/
 [380l]:https://leetcode.cn/problems/insert-delete-getrandom-o1/
 [382l]:https://leetcode.cn/problems/linked-list-random-node/