POJ 2371 Questions and answers
Time Limit: 1000MS | Memory Limit: 65536K | |
Total Submissions: 10646 | Accepted: 5645 |
Description
The database of the Pentagon contains a top-secret information. We don't know what the information is — you know, it's top-secret, — but we know the format of its representation. It is extremely simple. We don't know why, but all the data is coded by the natural numbers from 1 up to 5000. The size of the main base (we'll denote it be N) is rather big — it may contain up to 100 000 those numbers. The database is to process quickly every query. The most often query is: "Which element is i-th by its value?"— with i being a natural number in a range from 1 to N.
Your program is to play a role of a controller of the database. In the other words, it should be able to process quickly queries like this.
Your program is to play a role of a controller of the database. In the other words, it should be able to process quickly queries like this.
Input
The
standard input of the problem consists of two parts. At first, a
database is written, and then there's a sequence of queries. The format
of database is very simple: in the first line there's a number N, in the
next N lines there are numbers of the database one in each line in an
arbitrary order. A sequence of queries is written simply as well: in the
first line of the sequence a number of queries K (1 <= K <= 100)
is written, and in the next K lines there are queries one in each line.
The query "Which element is i-th by its value?" is coded by the number
i. A database is separated from a sequence of queries by the string of
three symbols "#".
Output
The
output should consist of K lines. In each line there should be an
answer to the corresponding query. The answer to the query "i" is an
element from the database, which is i-th by its value (in the order from
the least up to the greatest element).
Sample Input
5
7
121
123
7
121
###
4
3
3
2
5
Sample Output
121
121
7
123
排序,输出第K项
CODE:
#include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #define REP(i, s, n) for(int i = s; i <= n; i ++) #define REP_(i, s, n) for(int i = n; i >= s; i --) #define MAX_N 100000 + 10 using namespace std; int main(){ int n, a[MAX_N]; scanf("%d", &n); REP(i, 1, n) scanf("%d", &a[i]); sort(a + 1, a + 1 + n); int m, x; char s[4]; cin >> s; scanf("%d", &m); while(m --){ scanf("%d", &x); printf("%d\n", a[x]); } return 0; }