Codechef: Positive AND

Author: rahulp99

CompetitiveProgramming/CodeChef/P42_POSAND.py

@@ -0,0 +1,36 @@
+def main():
+    t = int(input())
+    res = [2,3,1]
+    last = 3
+    check = 4
+    for _ in range(t):
+        n = int(input())
+        if n == 1:
+            print(1)
+        elif (n & (n-1)) == 0:
+            print(-1)
+        elif n <= last:
+            for i in range(n):
+                print(res[i], end=" ")
+            print()
+        else:
+            for i in range(last):
+                print(res[i], end=" ")
+            last += 1
+            while last <= n:
+                if last == check:
+                    res.append(last + 1)
+                    res.append(last)
+                    print((last + 1), end=" ")
+                    print(last, end=" ")
+                    last += 2
+                    check *= 2
+                else:
+                    print(last, end=" ")
+                    res.append(last)
+                    last += 1
+            print()
+            last -= 1
+    return 0
+
+main()