골드바흐 시리즈 6588, 9020, 17103 complete

zeta_python/completed/17103.py

@@ -0,0 +1,27 @@
+import sys
+
+T = int(sys.stdin.readline())
+
+P = [2]
+K = [0] * 1000005
+K[2] = True
+for i in range(2, 1000000 - 1):
+    for p in P:
+        if i % p == 0:
+            break
+        elif p * p > i:
+            P.append(i)
+            K[i] = 1
+            break
+    else:
+        P.append(i)
+        K[i] = 1
+        break
+for _ in range(T):
+    n = int(sys.stdin.readline())
+    c = 0
+    for i in range(2, n//2+1):
+        if K[i] and K[n - i]:
+            c += 1
+        i += 1
+    print(c)