백준(BaekJoon)_15650_N과 M(2)

res = []

def func(n,m):
    if len(res) == m:
        test = res[:]
        test.sort()
        if (test == res):
            for ele in res:
                print(ele, end= " ")
            print()
            return
     
    else:
        for i in range(1,n+1):
            if i not in res:
                res.append(i)
                func(n,m)
                res.pop()  
    



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

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# 다른풀이
n,m = list(map(int,input().split()))
result = []
def func(start):
    if m == len(result):
        print(" ".join(map(str, result)))
        return 
    else:
        for i in range(start, n+1):
            if i not in result:
                result.append(i)
                func(start+1)  # i + 1를 함으로써, 처음의 i보다 큰수부터 동작하도로 했다
                result.pop()
func(1)


# 참고 https://jiwon-coding.tistory.com/22?category=882771