Codeforces Round #182 (Div. 2) / 302A Eugeny and Array(模拟)

A. Eugeny and Array

http://codeforces.com/problemset/problem/302/A

time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

Eugeny has array a = a₁, a₂, ..., a_n, consisting of n integers. Each integer a_i equals to -1, or to 1. Also, he has m queries:

• Query number i is given as a pair of integers l_i, r_i (1 ≤ l_i ≤ r_i ≤ n).
• The response to the query will be integer 1, if the elements of array a can be rearranged so as the sum a_li + a_li + 1 + ... + a_ri = 0, otherwise the response to the query will be integer 0.

Help Eugeny, answer all his queries.

Input

The first line contains integers n and m (1 ≤ n, m ≤ 2·10⁵). The second line contains n integers a₁, a₂, ..., a_n (a_i = -1, 1). Next mlines contain Eugene's queries. The i-th line contains integers l_i, r_i (1 ≤ l_i ≤ r_i ≤ n).

Output

Print m integers — the responses to Eugene's queries in the order they occur in the input.

Sample test(s)

input

2 31 -11 11 22 2

output

010

input

5 5-1 1 1 1 -11 12 33 52 51 5

output

01010

写第一遍没看清题意，样例2看不懂，后来发现我确实要补补英语了。。（不过这句话确实很容易漏掉）

原文有这么一句话：

" if the elements of array a can be rearranged ..."（如果序列a中元素经过重新排列后…）

完整代码：

/*171ms,0KB*/#include<cstdio>int main(){int n, m, a;int c1 = 0, c2 = 0;int l, r;scanf("%d%d", &n, &m);while (n--){scanf("%d", &a);if (a > 0)++c1;else++c2;}while (m--){scanf("%d%d", &l, &r);a = r - l + 1;///第一次交的时候这里写反了，WA4，罪过，罪过。。。if (a & 1)puts("0");else{a >>= 1;puts(c1 < a || c2 < a ? "0" : "1");}}return 0;}