Package g0401_0500.s0494_target_sum

Class Solution

java.lang.Object

g0401_0500.s0494_target_sum.Solution

public class Solution
extends Object

494 - Target Sum.<p>Medium</p> <p>You are given an integer array <code>nums</code> and an integer <code>target</code>.</p> <p>You want to build an <strong>expression</strong> out of nums by adding one of the symbols <code>'+'</code> and <code>'-'</code> before each integer in nums and then concatenate all the integers.</p> <ul> <li>For example, if <code>nums = [2, 1]</code>, you can add a <code>'+'</code> before <code>2</code> and a <code>'-'</code> before <code>1</code> and concatenate them to build the expression <code>&quot;+2-1&quot;</code>.</li> </ul> <p>Return the number of different <strong>expressions</strong> that you can build, which evaluates to <code>target</code>.</p> <p><strong>Example 1:</strong></p> <p><strong>Input:</strong> nums = [1,1,1,1,1], target = 3</p> <p><strong>Output:</strong> 5</p> <p><strong>Explanation:</strong></p> <pre><code> There are 5 ways to assign symbols to make the sum of nums be target 3. -1 + 1 + 1 + 1 + 1 = 3 +1 - 1 + 1 + 1 + 1 = 3 +1 + 1 - 1 + 1 + 1 = 3 +1 + 1 + 1 - 1 + 1 = 3 +1 + 1 + 1 + 1 - 1 = 3 </code></pre> <p><strong>Example 2:</strong></p> <p><strong>Input:</strong> nums = [1], target = 1</p> <p><strong>Output:</strong> 1</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= nums.length <= 20</code></li> <li><code>0 <= nums[i] <= 1000</code></li> <li><code>0 <= sum(nums[i]) <= 1000</code></li> <li><code>-1000 <= target <= 1000</code></li> </ul>

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
int	findTargetSumWays(int[] nums, int s)

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

findTargetSumWays

public int findTargetSumWays(int[] nums,
 int s)