Queue的push和front操作，queuepushfront
#include <queue>
#include <cstdlib>
using namespace std;
int main(){
queue<int> que;
que.push(1);
que.push(2);
que.push(3);
printf("%d\n", que.front());
que.pop();
printf("%d\n", que.front());
que.pop();
printf("%d\n", que.front());
system("pause");
return 0;
}
