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, ..., an,
consisting of n integers. Each integer ai equals
to -1, or to 1. Also, he has m queries:

Query number i is given as a pair of integers li, ri (1 ≤ li ≤ ri ≤ n).

The response to the query will be integer 1, if the elements of array a can
be rearranged so as the sum ali + ali + 1 + ... + ari = 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, ..., an (ai = -1, 1).
Next mlines contain Eugene's queries. The i-th line
contains integers li, ri (1 ≤ li ≤ ri ≤ n).

Output

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

Sample test(s)

input

2 3
1 -1
1 1
1 2
2 2

output

0
1
0

input

5 5
-1 1 1 1 -1
1 1
2 3
3 5
2 5
1 5

output

0
1
01
0

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;
}