90차 1번 문제 풀이

Author: gmlrude

live8/test90/문제1/박희경.py

@@ -0,0 +1,22 @@
+import sys
+
+input = sys.stdin.readline
+
+n = int(input())
+a = sorted(list(map(int, input().split())))
+x = int(input())
+
+i, j = 0, n - 1
+cnt = 0
+while i < j:
+    total = a[i] + a[j]
+    if total == x:
+        cnt += 1
+        i += 1
+        j -= 1
+    elif total > x:
+        j -= 1
+    else:
+        i += 1
+
+print(cnt)