![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 #include <stdio.h> 2 #include <string.h> 3 #include <queue> 4 #include <algorithm> 5 using namespace std; 6 7 int main() 8 { 9 queue <int> que; 10 while(que.size()) 11 que.pop(); 12 que.push(1); 13 que.push(2); 14 que.push(3); 15 printf("%d ",que.front()); 16 que.pop(); 17 printf("%d ",que.front()); 18 que.pop(); 19 printf("%d ",que.front()); 20 return 0; 21 }