java.lang.Object
g2001_2100.s2023_number_of_pairs_of_strings_with_concatenation_equal_to_target.Solution

public class Solution extends Object
2023 - Number of Pairs of Strings With Concatenation Equal to Target.<p>Medium</p> <p>Given an array of <strong>digit</strong> strings <code>nums</code> and a <strong>digit</strong> string <code>target</code>, return <em>the number of pairs of indices</em> <code>(i, j)</code> <em>(where</em> <code>i != j</code><em>) such that the <strong>concatenation</strong> of</em> <code>nums[i] + nums[j]</code> <em>equals</em> <code>target</code>.</p> <p><strong>Example 1:</strong></p> <p><strong>Input:</strong> nums = [&ldquo;777&rdquo;,&ldquo;7&rdquo;,&ldquo;77&rdquo;,&ldquo;77&rdquo;], target = &ldquo;7777&rdquo;</p> <p><strong>Output:</strong> 4</p> <p><strong>Explanation:</strong> Valid pairs are:</p> <ul> <li> <p>(0, 1): &ldquo;777&rdquo; + &ldquo;7&rdquo;</p> </li> <li> <p>(1, 0): &ldquo;7&rdquo; + &ldquo;777&rdquo;</p> </li> <li> <p>(2, 3): &ldquo;77&rdquo; + &ldquo;77&rdquo;</p> </li> <li> <p>(3, 2): &ldquo;77&rdquo; + &ldquo;77&rdquo;</p> </li> </ul> <p><strong>Example 2:</strong></p> <p><strong>Input:</strong> nums = [&ldquo;123&rdquo;,&ldquo;4&rdquo;,&ldquo;12&rdquo;,&ldquo;34&rdquo;], target = &ldquo;1234&rdquo;</p> <p><strong>Output:</strong> 2</p> <p><strong>Explanation:</strong> Valid pairs are:</p> <ul> <li> <p>(0, 1): &ldquo;123&rdquo; + &ldquo;4&rdquo;</p> </li> <li> <p>(2, 3): &ldquo;12&rdquo; + &ldquo;34&rdquo;</p> </li> </ul> <p><strong>Example 3:</strong></p> <p><strong>Input:</strong> nums = [&ldquo;1&rdquo;,&ldquo;1&rdquo;,&ldquo;1&rdquo;], target = &ldquo;11&rdquo;</p> <p><strong>Output:</strong> 6</p> <p><strong>Explanation:</strong> Valid pairs are:</p> <ul> <li> <p>(0, 1): &ldquo;1&rdquo; + &ldquo;1&rdquo;</p> </li> <li> <p>(1, 0): &ldquo;1&rdquo; + &ldquo;1&rdquo;</p> </li> <li> <p>(0, 2): &ldquo;1&rdquo; + &ldquo;1&rdquo;</p> </li> <li> <p>(2, 0): &ldquo;1&rdquo; + &ldquo;1&rdquo;</p> </li> <li> <p>(1, 2): &ldquo;1&rdquo; + &ldquo;1&rdquo;</p> </li> <li> <p>(2, 1): &ldquo;1&rdquo; + &ldquo;1&rdquo;</p> </li> </ul> <p><strong>Constraints:</strong></p> <ul> <li><code>2 <= nums.length <= 100</code></li> <li><code>1 <= nums[i].length <= 100</code></li> <li><code>2 <= target.length <= 100</code></li> <li><code>nums[i]</code> and <code>target</code> consist of digits.</li> <li><code>nums[i]</code> and <code>target</code> do not have leading zeros.</li> </ul>
  • Constructor Details

    • Solution

      public Solution()
  • Method Details

    • numOfPairs

      public int numOfPairs(String[] nums, String target)