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"content": "<p>Given an array of <strong>distinct</strong> integers <code>nums</code> and a target integer <code>target</code>, return <em>the number of possible combinations that add up to</em> <code>target</code>.</p>\n\n<p>The test cases are generated so that the answer can fit in a <strong>32-bit</strong> integer.</p>\n\n<p> </p>\n<p><strong>Example 1:</strong></p>\n\n<pre>\n<strong>Input:</strong> nums = [1,2,3], target = 4\n<strong>Output:</strong> 7\n<strong>Explanation:</strong>\nThe possible combination ways are:\n(1, 1, 1, 1)\n(1, 1, 2)\n(1, 2, 1)\n(1, 3)\n(2, 1, 1)\n(2, 2)\n(3, 1)\nNote that different sequences are counted as different combinations.\n</pre>\n\n<p><strong>Example 2:</strong></p>\n\n<pre>\n<strong>Input:</strong> nums = [9], target = 3\n<strong>Output:</strong> 0\n</pre>\n\n<p> </p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>1 <= nums.length <= 200</code></li>\n\t<li><code>1 <= nums[i] <= 1000</code></li>\n\t<li>All the elements of <code>nums</code> are <strong>unique</strong>.</li>\n\t<li><code>1 <= target <= 1000</code></li>\n</ul>\n\n<p> </p>\n<p><strong>Follow up:</strong> What if negative numbers are allowed in the given array? How does it change the problem? What limitation we need to add to the question to allow negative numbers?</p>\n",
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