Codeforces Round #159 (Div. 2)

A: I can't understand the question. I can directly view B in the sample. I can directly output--C: equivalent to sorting n rays and edges, and then find the two adjacent bars with the largest angle, 360 minus this angle is the answer D: The last item minus the last and second items must be less than or equal to the last and second items, and then the difference is different from the last and third items (large Minus small ), the result must be less than or equal to the last and third item. Then, recurrence is performed in sequence, which is equivalent to constant parentheses. Finally, parentheses are removed from left to right to prove: assume that the last three items are a + d1 a + d1 + d2, then d2 <= a + d1 if d2> =, then 0 <= d2-a <= d1 <= a otherwise 0 <= a-d2 <= a so as long as the big minus small certainly can meet the obtained last number is greater than or equal 0 and less than or equal to the first item. E: gaoing