添加了许多代码文件

「7-1」A、队列的基本操作.cpp

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+#include <algorithm>
+#include <iostream>
+#include <iomanip>
+#include <cstring>
+#include <cstdio>
+#include <stack>
+#include <ctime>
+#include <cmath>
+#include <queue>
+typedef long long l;
+typedef double d;
+typedef char c;
+using namespace std;
+string b;
+queue<int> que;
+int main(){
+	freopen("A.in","r",stdin);
+	freopen("A.out","w",stdout);
+	int a;
+	cin >>a;
+	for(int i=0;i<a;i++){
+		cin >>b;
+		if(b=="push"){
+			int x;
+			cin >>x;
+			que.push(x); 
+		}
+		else if(b=="front" && que.empty()==0){
+			cout <<que.front()<<endl;
+		}
+		else if(b=="front" && que.empty()==1){
+			cout <<"error"<<endl;
+		}
+		else if(b=="pop" && que.empty()==0){
+			que.pop();
+		}
+		else if(b=="pop" && que.empty()==1){
+			cout <<"error"<<endl;
+		}
+		else if(b=="empty"){
+			if(que.empty()==1){
+				cout <<"empty"<<endl;
+			}
+			if(que.empty()==0){
+				cout <<"not empty"<<endl;
+			}
+		}
+		else if(b=="clear"){
+			while(que.empty()!=true){
+				que.pop();
+			}
+		} 
+	}
+	return 0;
+}