题解 | #牛棚分组#

所用语言

java

所用知识

递归、数组

解题思路

完整代码

ArrayList<ArrayList<Integer>> lists = new
ArrayList<ArrayList<Integer>>();
public int[][] combine (int n, int k) {
    // write code here
    search(1,k,n,new ArrayList<>());
    int[][] arr = new int[lists.size()][k];
    for(int i=0;i<lists.size();i++){
        for(int j=0;j<lists.get(i).size();j++){
            arr[i][j] = lists.get(i).get(j);
        }
    }
    return arr;
}

public void search(int cur,int cap,int n,ArrayList<Integer> list){
    if(list.size()==cap){
        lists.add(new ArrayList<>(list));
        return;
    }
    if(cur>n){
        return;
    }
    list.add(cur);
    search(cur+1,cap,n,list);
    list.remove(list.size()-1);
    search(cur+1,cap,n,list);
}