小米OJ 12. 找出可能的合的组合

var sum = 0;
var nums;

function solution(line) {
    var str = line.split(" ");
    nums = str[0].split(",");
    var num = parseInt(str[1]);
    dfs(num, nums.length - 1);
    return sum + "";
}

function dfs(target, curNum) {
    if (target < 0 || curNum < 0) {
        return;
    }
    if (target === 0) {
        sum++;
        return;
    }
    dfs(target - nums[curNum], curNum - 1);
    dfs(target - nums[curNum], curNum);
    dfs(target, curNum - 1);
}