[백준] 15655번 n과 m(6)

n,m=map(int,input().split())

num=list(map(int,input().split()))
num.sort()
s=[]
def dfs(cnt,i):
    if cnt==m:
        for x in s:
            print(x,end=' ')
        print()
        return
    for i in range(i,n):
        if num[i] not in s:
            s.append(num[i])
            dfs(cnt+1,i)
            s.pop()

dfs(0,0)