Have you ever thought about how many people are transported by trams every
year in a city with a ten-million population where one in three citizens uses
tram twice a day?
Assume that there are n cities with trams on the planet Earth.
Statisticians counted for each of them the number of people transported by
trams during last year. They compiled a table, in which cities were sorted
alphabetically. Since city names were inessential for statistics, they were
later replaced by numbers from 1 to n. A search engine that works with
these data must be able to answer quickly a query of the following type: is
there among the cities with numbers from l to r such that the
trams of this city transported exactly x people during last year. You
must implement this module of the system.
The first line contains the integer n, 0 <
n < 70000. The second line contains statistic data in the form of a
list of integers separated with a space. In this list, the ith number is
the number of people transported by trams of the ith city during last
year. All numbers in the list are positive and do not exceed
109 − 1. In the third line, the number of queries
q is given, 0 < q < 70000. The next q
lines contain the queries. Each of them is a triple of integers l,
r, and x separated with a space; 1 ≤ l ≤
r ≤ n; 0 < x < 109.
Output a string of length q in which the
ith symbol is “1” if the answer to the ith query is
affirmative, and “0” otherwise.
1234567 666666 3141593 666666 4343434
1 5 3141593
1 5 578202
2 4 666666
4 4 7135610
1 1 1234567
Problem Author: Alexander Ipatov
Problem Source: The 12th Urals Collegiate Programing Championship, March 29, 2008