poj 1442 Black Box
Black Box
Time Limit: 1000MS | Memory Limit: 10000K | |
Total Submissions: 8847 | Accepted: 3636 |
Description
Our Black Box represents a primitive database. It can save an integer array and has a special i variable. At the initial moment Black Box is empty and i equals 0. This Black Box processes a sequence of commands (transactions). There are two types of transactions:
ADD (x): put element x into Black Box;
GET: increase i by 1 and give an i-minimum out of all integers containing in the Black Box. Keep in mind that i-minimum is a number located at i-th place after Black Box elements sorting by non- descending.
Let us examine a possible sequence of 11 transactions:
Example 1
It is required to work out an efficient algorithm which treats a given sequence of transactions. The maximum number of ADD and GET transactions: 30000 of each type.
Let us describe the sequence of transactions by two integer arrays:
1. A(1), A(2), ..., A(M): a sequence of elements which are being included into Black Box. A values are integers not exceeding 2 000 000 000 by their absolute value, M <= 30000. For the Example we have A=(3, 1, -4, 2, 8, -1000, 2).
2. u(1), u(2), ..., u(N): a sequence setting a number of elements which are being included into Black Box at the moment of first, second, ... and N-transaction GET. For the Example we have u=(1, 2, 6, 6).
The Black Box algorithm supposes that natural number sequence u(1), u(2), ..., u(N) is sorted in non-descending order, N <= M and for each p (1 <= p <= N) an inequality p <= u(p) <= M is valid. It follows from the fact that for the p-element of our u sequence we perform a GET transaction giving p-minimum number from our A(1), A(2), ..., A(u(p)) sequence.
ADD (x): put element x into Black Box;
GET: increase i by 1 and give an i-minimum out of all integers containing in the Black Box. Keep in mind that i-minimum is a number located at i-th place after Black Box elements sorting by non- descending.
Let us examine a possible sequence of 11 transactions:
Example 1
N Transaction i Black Box contents after transaction Answer (elements are arranged by non-descending) 1 ADD(3) 0 3 2 GET 1 3 3 3 ADD(1) 1 1, 3 4 GET 2 1, 3 3 5 ADD(-4) 2 -4, 1, 3 6 ADD(2) 2 -4, 1, 2, 3 7 ADD(8) 2 -4, 1, 2, 3, 8 8 ADD(-1000) 2 -1000, -4, 1, 2, 3, 8 9 GET 3 -1000, -4, 1, 2, 3, 8 1 10 GET 4 -1000, -4, 1, 2, 3, 8 2 11 ADD(2) 4 -1000, -4, 1, 2, 2, 3, 8
It is required to work out an efficient algorithm which treats a given sequence of transactions. The maximum number of ADD and GET transactions: 30000 of each type.
Let us describe the sequence of transactions by two integer arrays:
1. A(1), A(2), ..., A(M): a sequence of elements which are being included into Black Box. A values are integers not exceeding 2 000 000 000 by their absolute value, M <= 30000. For the Example we have A=(3, 1, -4, 2, 8, -1000, 2).
2. u(1), u(2), ..., u(N): a sequence setting a number of elements which are being included into Black Box at the moment of first, second, ... and N-transaction GET. For the Example we have u=(1, 2, 6, 6).
The Black Box algorithm supposes that natural number sequence u(1), u(2), ..., u(N) is sorted in non-descending order, N <= M and for each p (1 <= p <= N) an inequality p <= u(p) <= M is valid. It follows from the fact that for the p-element of our u sequence we perform a GET transaction giving p-minimum number from our A(1), A(2), ..., A(u(p)) sequence.
Input
Input contains (in given order): M, N, A(1), A(2), ..., A(M), u(1), u(2), ..., u(N). All numbers are divided by spaces and (or) carriage return characters.
Output
Write to the output Black Box answers sequence for a given sequence of transactions, one number each line.
Sample Input
7 4 3 1 -4 2 8 -1000 2 1 2 6 6
Sample Output
3 3 12
题目大意: 给出两种操作例如以下:( ADD GET ) 操作 当GET取第几大 全部已加入元素 输出的元素 1 ADD(3) 0 3 2 GET 1 3 3 3 ADD(1) 1 1, 3 4 GET 2 1, 3 3 5 ADD(-4) 2 -4, 1, 3 6 ADD(2) 2 -4, 1, 2, 3 7 ADD(8) 2 -4, 1, 2, 3, 8 8 ADD(-1000) 2 -1000, -4, 1, 2, 3, 8 9 GET 3 -1000, -4, 1, 2, 3, 8 1 10 GET 4 -1000, -4, 1, 2, 3, 8 2 11 ADD(2) 4 -1000, -4, 1, 2, 2, 3, 8 用给出的输入实现以上操作。原本是想队列写的,但超时:
#include<stdio.h> #include<queue> #include<iostream> #include<algorithm> using namespace std; int main() { int n,m; while(scanf("%d%d",&n,&m)!=EOF) { priority_queue<int ,vector<int >,greater<int > >q; priority_queue<int ,vector<int >,greater<int > >p; priority_queue<int ,vector<int >,less<int > >u; int a[40000],v,i; for(i=0;i<n;i++) scanf("%d",&a[i]); for(i=0;i<m;i++) { scanf("%d",&v); q.push(v); } int temp,s,b; int j=1; while(!q.empty() ) { int k=j; i=0; temp=q.top() ; q.pop() ; while(temp>i) { p.push(a[i]); i++; } while(!u.empty() ) u.pop() ; while(k--) { b=p.top(); p.pop() ; u.push(b); } int s; s=u.top(); printf("%d\n",s); while(!p.empty() ) p.pop() ; j++; } } }这是A的:(优先队列)#include <stdio.h> #include <queue> using namespace std; int main() { int a[30005],i,j,n,m; while(scanf("%d%d",&n,&m)!=EOF) { int cut=0,x,c=0,t; for(i=0; i<n; i++) { scanf("%d",&a[i]); } priority_queue <int , vector <int> , less<int> > p; //大顶堆 priority_queue <int , vector <int> , greater<int> >q; for(i=0; i<m; i++) { scanf("%d",&x); while(c<x) { q.push(a[c]); c++; } while(!p.empty()&&p.top()>q.top()) //保证P的元素一定比q小 { t=p.top(); p.pop(); p.push(q.top()); q.pop(); q.push(t); } printf("%d\n",q.top()); p.push(q.top()); q.pop(); } } return 0; }