Package g0901_1000.s0923_3sum_with_multiplicity

Class Solution

java.lang.Object

g0901_1000.s0923_3sum_with_multiplicity.Solution

public class Solution
extends Object

923 - 3Sum With Multiplicity.<p>Medium</p> <p>Given an integer array <code>arr</code>, and an integer <code>target</code>, return the number of tuples <code>i, j, k</code> such that <code>i < j < k</code> and <code>arr[i] + arr[j] + arr[k] == target</code>.</p> <p>As the answer can be very large, return it <strong>modulo</strong> <code>10⁹ + 7</code>.</p> <p><strong>Example 1:</strong></p> <p><strong>Input:</strong> arr = [1,1,2,2,3,3,4,4,5,5], target = 8</p> <p><strong>Output:</strong> 20</p> <p><strong>Explanation:</strong></p> <pre><code> Enumerating by the values (arr[i], arr[j], arr[k]): (1, 2, 5) occurs 8 times; (1, 3, 4) occurs 8 times; (2, 2, 4) occurs 2 times; (2, 3, 3) occurs 2 times. </code></pre> <p><strong>Example 2:</strong></p> <p><strong>Input:</strong> arr = [1,1,2,2,2,2], target = 5</p> <p><strong>Output:</strong> 12</p> <p><strong>Explanation:</strong></p> <p>arr[i] = 1, arr[j] = arr[k] = 2 occurs 12 times:</p> <p>We choose one 1 from [1,1] in 2 ways,</p> <p>and two 2s from [2,2,2,2] in 6 ways.</p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 <= arr.length <= 3000</code></li> <li><code>0 <= arr[i] <= 100</code></li> <li><code>0 <= target <= 300</code></li> </ul>

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
int	threeSumMulti(int[] arr, int target)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Solution

public Solution()

Method Details

threeSumMulti

public int threeSumMulti(int[] arr,
 int target)