uva 11995 I Can Guess the Data Structure!

Posted 2020-08-15 SBSOI

模拟

There is a bag-like data structure, supporting two operations: 1 x Throw an element x into the bag. 2 Take out an element from the bag. Given a sequence of operations with return values, you’re going to guess the data structure. It is a stack (Last-In, First-Out), a queue (First-In, First-Out), a priority-queue (Always take out larger elements first) or something else that you can hardly imagine! Input There are several test cases. Each test case begins with a line containing a single integer n (1 ≤ n ≤ 1000). Each of the next n lines is either a type-1 command, or an integer 2 followed by an integer x. That means after executing a type-2 command, we get an element x without error. The value of x is always a positive integer not larger than 100. The input is terminated by end-of-file (EOF). Output For each test case, output one of the following: stack It’s definitely a stack. queue It’s definitely a queue. priority queue It’s definitely a priority queue. impossible It can’t be a stack, a queue or a priority queue. not sure It can be more than one of the three data structures mentioned above.

Sample Input

6 1 1 1 2 1 3 2 1 2 2 2 3 6 1 1 1 2 1 3 2 3 2 2 2 1 2 1 1 2 2 4 1 2 1 1 2 1 2 2 7 1 2 1 5 1 1 1 3 2 5 1 4 2 4

Sample Output

queue not sure impossible stack priority queue

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纯模拟题目。

祝大家都ak愉快。

 1 /*
 2     Problem:
 3     OJ:
 4     User:    S.B.S.
 5     Time:
 6     Memory:
 7     Length:
 8 */
 9 #include<bits/stdc++.h>
10 #include<iostream>
11 #include<cstdio>
12 #include<cstring>
13 #include<cmath>
14 #include<algorithm>
15 #include<queue>
16 #include<cstdlib>
17 #include<iomanip>
18 #include<cassert>
19 #include<climits>
20 #include<functional>
21 #include<stack>
22 #include<bitset>
23 #include<vector>
24 #include<list>
25 #define F(i,j,k) for(int i=j;i<k;++i)
26 #define M(a,b) memset(a,b,sizeof(a))
27 #define FF(i,j,k) for(int i=j;i>=k;i--)
28 #define maxn 10001
29 #define inf 0x3f3f3f3f
30 #define maxm 4001
31 #define mod 998244353
32 #define LOCAL
33 using namespace std;
34 int read(){
35     int x=0,f=1;char ch=getchar();
36     while(ch<\'0\'||ch>\'9\'){if(ch==\'-\')f=-1;ch=getchar();}
37     while(ch>=\'0\'&&ch<=\'9\'){x=x*10+ch-\'0\';ch=getchar();}
38     return x*f;
39 }
40 int n,m;
41 struct POINT
42 {
43     int id;
44     int data;
45     friend bool operator < (POINT a,POINT b){return a.data < b.data;}
46 }d[maxn];
47 inline bool pdstk()
48 {
49     stack<int> stk;
50     F(i,0,n){
51         if(d[i].id==1) stk.push(d[i].data);
52         if(d[i].id==2){
53             if(stk.empty()) return false;
54             if(stk.top()==d[i].data){stk.pop();continue;}
55             else return false;
56         }
57     }
58     return true;
59 }
60 inline bool pdque()
61 {
62     queue<int> q;
63     F(i,0,n){
64         if(d[i].id==1) q.push(d[i].data);
65         if(d[i].id==2){
66             if(q.empty()) return false;
67             if (q.front()==d[i].data){q.pop();continue;}
68               else return 0;
69         }
70     }
71     return true;
72 }
73 inline bool pdheap()
74 {
75     priority_queue<POINT> h;
76     F(i,0,n){
77         if (d[i].id==1) h.push(d[i]);
78         if(d[i].id==2){
79               if(h.empty()) return false;
80               if(h.top().data==d[i].data){h.pop();continue;}
81               else return 0;
82           }
83     }
84     return true;
85 }
86 int main()
87 {
88     std::ios::sync_with_stdio(false);//cout<<setiosflags(ios::fixed)<<setprecision(1)<<y;
89     #ifdef LOCAL
90     freopen("qu.in","r",stdin);
91     freopen("qu.out","w",stdout);
92     #endif
93     cin>>n;
94     F(i,0,n) cin>>d[i].id>>d[i].data;
95     if(pdstk()) cout<<"YES"<<endl;else cout<<"No"<<endl;
96     if(pdque()) cout<<"YES"<<endl;else cout<<"No"<<endl;
97     if(pdheap()) cout<<"YES"<<endl;else cout<<"No"<<endl;
98     return 0;
99 }

uva 11995