Combination Sum

Description

Given a set of candidate numbers (candidates) (without duplicates) and a target number (target), find all unique combinations in candidates where the candidate numbers sums to target.

The same repeated number may be chosen from candidates unlimited number of times.

Note:

• All numbers (including target) will be positive integers.
• The solution set must not contain duplicate combinations.

Example 1:

Input: candidates = [2,3,6,7], target = 7,
A solution set is:
[
  [7],
  [2,2,3]
]

Example 2:

Input: candidates = [2,3,5], target = 8,
A solution set is:
[
  [2,2,2,2],
  [2,3,3],
  [3,5]
]

Solution(javascript)

/**
 * @param {number[]} candidates
 * @param {number} target
 * @return {number[][]}
 */
var combinationSum = function(candidates, target) {
    function findCom(cans, target, rst, arr) {
        if(target === 0){
            rst.push(arr);
        } else {
            for(let i = 0; i < cans.length; i++){
                if(cans[i] <= target){
                    let newArr = arr.slice();
                    newArr.push(cans[i]);
                    findCom(cans.slice(i), target-cans[i], rst, newArr);
                }
            }
        }
    }
    
    candidates.sort((a, b) => a - b);
    let rst = new Array();
    for(let i = 0; i < candidates.length; i++){
        if(candidates[i] <= target){
            findCom(candidates.slice(i), target-candidates[i], rst, [candidates[i]]);
        }
    }
    
    return rst;
};