Package g0401_0500.s0454_4sum_ii

Class Solution

java.lang.Object

g0401_0500.s0454_4sum_ii.Solution

public class Solution
extends Object

454 - 4Sum II.<p>Medium</p> <p>Given four integer arrays <code>nums1</code>, <code>nums2</code>, <code>nums3</code>, and <code>nums4</code> all of length <code>n</code>, return the number of tuples <code>(i, j, k, l)</code> such that:</p> <ul> <li><code>0 <= i, j, k, l < n</code></li> <li><code>nums1[i] + nums2[j] + nums3[k] + nums4[l] == 0</code></li> </ul> <p><strong>Example 1:</strong></p> <p><strong>Input:</strong> nums1 = [1,2], nums2 = [-2,-1], nums3 = [-1,2], nums4 = [0,2]</p> <p><strong>Output:</strong> 2</p> <p><strong>Explanation:</strong> The two tuples are:</p> <ol> <li> <p>(0, 0, 0, 1) -> nums1[0] + nums2[0] + nums3[0] + nums4[1] = 1 + (-2) + (-1) + 2 = 0</p> </li> <li> <p>(1, 1, 0, 0) -> nums1[1] + nums2[1] + nums3[0] + nums4[0] = 2 + (-1) + (-1) + 0 = 0</p> </li> </ol> <p><strong>Example 2:</strong></p> <p><strong>Input:</strong> nums1 = [0], nums2 = [0], nums3 = [0], nums4 = [0]</p> <p><strong>Output:</strong> 1</p> <p><strong>Constraints:</strong></p> <ul> <li><code>n == nums1.length</code></li> <li><code>n == nums2.length</code></li> <li><code>n == nums3.length</code></li> <li><code>n == nums4.length</code></li> <li><code>1 <= n <= 200</code></li> <li><code>-2²⁸ <= nums1[i], nums2[i], nums3[i], nums4[i] <= 2²⁸</code></li> </ul>

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
int	fourSumCount(int[] nums1, int[] nums2, int[] nums3, int[] nums4)

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

fourSumCount

public int fourSumCount(int[] nums1,
 int[] nums2,
 int[] nums3,
 int[] nums4)