[boj]부분수열의 합

Author: windsor

BOJ/1182.부분수열의 합/6047198844.py

@@ -0,0 +1,26 @@
+from itertools import combinations
+
+#idx를 뽑거나 뽑지 않는 경우의수.
+#N개를 뽑았을때 합이 S면 True, 아니면 False반환
+#idx 현재 판단의 기준이되는 idx / 목표하는 합 S / 누적합 partial_sum
+def partial_sequence(idx:int, N:int, S:int, partial_sum:int, sequence:list):
+    if N < 0:
+        return 0
+    
+    if idx == len(sequence):
+        if partial_sum == S and N == 0:
+            return 1
+        return 0
+
+    res = 0
+    res += partial_sequence(idx+1, N-1, S, partial_sum+sequence[idx], sequence)
+    res += partial_sequence(idx+1, N, S, partial_sum, sequence)
+    return res
+
+N, S = map(int, input().split())
+sequence = list(map(int, input().split()))
+
+res = 0
+for _ in range(1,N+1):
+    res += partial_sequence(0, _, S, 0, sequence)
+print(res)