Package g0601_0700.s0679_24_game

Class Solution

java.lang.Object
g0601_0700.s0679_24_game.Solution
public class Solution extends Object
679 - 24 Game.<p>Hard</p> <p>You are given an integer array <code>cards</code> of length <code>4</code>. You have four cards, each containing a number in the range <code>[1, 9]</code>. You should arrange the numbers on these cards in a mathematical expression using the operators <code>['+', '-', '*', '/']</code> and the parentheses <code>'('</code> and <code>')'</code> to get the value 24.</p> <p>You are restricted with the following rules:</p> <ul> <li>The division operator <code>'/'</code> represents real division, not integer division. <ul> <li>For example, <code>4 / (1 - 2 / 3) = 4 / (1 / 3) = 12</code>.</li> </ul> </li> <li>Every operation done is between two numbers. In particular, we cannot use <code>'-'</code> as a unary operator. <ul> <li>For example, if <code>cards = [1, 1, 1, 1]</code>, the expression <code>&quot;-1 - 1 - 1 - 1&quot;</code> is <strong>not allowed</strong>.</li> </ul> </li> <li>You cannot concatenate numbers together <ul> <li>For example, if <code>cards = [1, 2, 1, 2]</code>, the expression <code>&quot;12 + 12&quot;</code> is not valid.</li> </ul> </li> </ul> <p>Return <code>true</code> if you can get such expression that evaluates to <code>24</code>, and <code>false</code> otherwise.</p> <p><strong>Example 1:</strong></p> <p><strong>Input:</strong> cards = [4,1,8,7]</p> <p><strong>Output:</strong> true</p> <p><strong>Explanation:</strong> (8-4) * (7-1) = 24</p> <p><strong>Example 2:</strong></p> <p><strong>Input:</strong> cards = [1,2,1,2]</p> <p><strong>Output:</strong> false</p> <p><strong>Constraints:</strong></p> <ul> <li><code>cards.length == 4</code></li> <li><code>1 <= cards[i] <= 9</code></li> </ul>

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • judgePoint24

      public boolean judgePoint24(int[] nums)