Combination Sum II

Problem Description

Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sum to target.

Each number in candidates may only be used once in the combination.

Note: The solution set must not contain duplicate combinations.

Example 1:

Input: candidates = [10,1,2,7,6,1,5], target = 8
Output: 
[
[1,1,6],
[1,2,5],
[1,7],
[2,6]
]

Example 2:

Input: candidates = [2,5,2,1,2], target = 5
Output: 
[
[1,2,2],
[5]
]

Constraints:

• 1 <= candidates.length <= 100
• 1 <= candidates[i] <= 50
• 1 <= target <= 30

Solution (JavaScript)

/**
 * @param {number[]} candidates
 * @param {number} target
 * @return {number[][]}
 */
var combinationSum2 = function(candidates, target) {
    function findCom(cans, target, rst, arr) {
        if(target === 0){
            rst.push(arr);
        } else {
            let last = -1;
            for(let i = 0; i < cans.length; i++){
                if(last != cans[i] && cans[i] <= target){
                    let newArr = arr.slice();
                    newArr.push(cans[i]);
                    findCom(cans.slice(i+1), target-cans[i], rst, newArr);
                }
                last = cans[i];
            }
        }
    }
    
    candidates.sort((a, b) => a - b);
    let rst = new Array();
    let last = -1;
    for(let i = 0; i < candidates.length; i++){
        if(last != candidates[i] && candidates[i] <= target){
            findCom(candidates.slice(i+1), target-candidates[i], rst, [candidates[i]]);
        }
        last = candidates[i];
    }
    
    return rst;
};