{"id":3119,"date":"2018-07-13T19:17:52","date_gmt":"2018-07-14T02:17:52","guid":{"rendered":"http:\/\/zxi.mytechroad.com\/blog\/?p=3119"},"modified":"2018-07-13T19:18:01","modified_gmt":"2018-07-14T02:18:01","slug":"leetcode-698-partition-to-k-equal-sum-subsets","status":"publish","type":"post","link":"https:\/\/zxi.mytechroad.com\/blog\/searching\/leetcode-698-partition-to-k-equal-sum-subsets\/","title":{"rendered":"\u82b1\u82b1\u9171 LeetCode 698. Partition to K Equal Sum Subsets"},"content":{"rendered":"

Problem<\/strong><\/h1>\n
\n
\n

Given an array of integers\u00a0nums<\/code>\u00a0and a positive integer\u00a0k<\/code>, find whether it’s possible to divide this array into\u00a0k<\/code>non-empty subsets whose sums are all equal.<\/p>\n

Example 1:<\/b><\/p>\n

Input:<\/b> nums = [4, 3, 2, 3, 5, 2, 1], k = 4\r\nOutput:<\/b> True\r\nExplanation:<\/b> It's possible to divide it into 4 subsets (5), (1, 4), (2,3), (2,3) with equal sums.\r\n<\/pre>\n
Note:<\/b><\/p>\n
    \n
  • 1 <= k <= len(nums) <= 16<\/code>.<\/li>\n
  • 0 < nums[i] < 10000<\/code>.<\/li>\n<\/ul>\n
    Solution: Search<\/strong><\/h1>\n
    Time complexity: O(n!)<\/p>\n
    Space complexity: O(n)<\/p>\n
    \/\/ Author: Huahua\r\n\/\/ Running time: 4 ms (<99.21%)\r\nclass Solution {\r\npublic:\r\n  bool canPartitionKSubsets(vector<int>& nums, int k) {\r\n    const int sum = accumulate(nums.begin(), nums.end(), 0);\r\n    if (sum % k != 0) return false;    \r\n    sort(nums.rbegin(), nums.rend());    \r\n    return dfs(nums, sum \/ k, 0, k, 0);\r\n  }\r\nprivate:\r\n  bool dfs(const vector<int>& nums, int target, int cur, int k, int used) {\r\n    if (k == 0) return used == (1 << nums.size()) - 1;\r\n    for (int i = 0; i < nums.size(); ++i) {\r\n      if (used & (1 << i)) continue;\r\n      int t = cur + nums[i];\r\n      if (t > target) break; \/\/ Important\r\n      int new_used = used | (1 << i);\r\n      if (t == target && dfs(nums, target, 0, k - 1, new_used)) return true; \r\n      else if (dfs(nums, target, t, k, new_used)) return true;\r\n    }\r\n    return false;\r\n  }  \r\n};<\/pre>\n
     <\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"
    Problem Given an array of integers\u00a0nums\u00a0and a positive integer\u00a0k, find whether it’s possible to divide this array into\u00a0knon-empty subsets whose sums are all equal. Example…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[44],"tags":[33,177,42,62],"class_list":["post-3119","post","type-post","status-publish","format-standard","hentry","category-searching","tag-dfs","tag-medium","tag-search","tag-sum","entry","simple"],"_links":{"self":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/3119","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/comments?post=3119"}],"version-history":[{"count":2,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/3119\/revisions"}],"predecessor-version":[{"id":3121,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/3119\/revisions\/3121"}],"wp:attachment":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/media?parent=3119"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/categories?post=3119"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/tags?post=3119"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}