| Time Limit | $2$ 秒/Second(s) | Memory Limit | $512$ 兆字节/Megabyte(s) |
| 提交总数 | $834$ | 正确数量 | $676$ | "
| 裁判形式 | 标准裁判/Standard Judge | 我的状态 | 尚未尝试 |
| 难度 | 分类标签 | STL |
Queue
Queue is a container of elements that are inserted and deleted according to FIFO (First In First Out).
For n queues Qi (i=0,1,...,n−1), perform a sequence of the following operations.
enqueue(t, x): Insert an integer x to Qt.
front(t): Report the value which should be deleted next from Qt. If Qt is empty, do nothing.
dequeue(t): Delete an element from Qt. If Qt is empty, do nothing.
In the initial state, all queues are empty.
The input is given in the following format.
n q
query1
query2
:
queryq
Each query queryi is given by 0 t x or 1 t or 2 t where the first digits 0, 1 and 2 represent enqueue, front and dequeue operations respectively. 1≤n≤1,000 1≤q≤200,000 −1,000,000,000≤x≤1,000,000,000
3 9
0 0 1
0 0 2
0 0 3
0 2 4
0 2 5
1 0
1 2
2 0
1 0
1
4
2