Problem J: Basic Data Structures - Queue

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Time Limit $2$ 秒/Second(s) Memory Limit $512$ 兆字节/Megabyte(s)
提交总数 $1195$ 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

For each front operation, print an integer in a line.
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