Package g0001_0100.s0039_combination_sum

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    39 - Combination Sum.

    Medium

    Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. You may return the combinations in any order.

    The same number may be chosen from candidates an unlimited number of times. Two combinations are unique if the frequency of at least one of the chosen numbers is different.

    It is guaranteed that the number of unique combinations that sum up to target is less than 150 combinations for the given input.

    Example 1:

    Input: candidates = 2,3,6,7, target = 7

    Output: [2,2,3,7]

    Explanation: 2 and 3 are candidates, and 2 + 2 + 3 = 7. Note that 2 can be used multiple times.

    7 is a candidate, and 7 = 7.

    These are the only two combinations.

    Example 2:

    Input: candidates = 2,3,5, target = 8

    Output: [2,2,2,2,2,3,3,3,5]

    Example 3:

    Input: candidates = 2, target = 1

    Output: []

    Constraints:

    • 1 <= candidates.length <= 30

    • 1 <= candidates[i] <= 200

    • All elements of candidates are distinct.

    • 1 <= target <= 500

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final List<List<Integer>> combinationSum(IntArray candidates, Integer target)

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait