Codeforces 129A-Cookies（暴力）

A. Cookies

time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

Olga came to visit the twins Anna and Maria and saw that they have many cookies. The cookies are distributed into bags. As there are many cookies, Olga decided that it's no big deal if she steals a bag. However, she doesn't want the sisters to quarrel because
of nothing when they divide the cookies. That's why Olga wants to steal a bag with cookies so that the number of cookies in the remaining bags was even, that is, so that Anna and Maria could evenly divide it into two (even 0 remaining cookies will do, just
as any other even number). How many ways there are to steal exactly one cookie bag so that the total number of cookies in the remaining bags was even?

Input

The first line contains the only integer n (1 ≤ n ≤ 100)
— the number of cookie bags Anna and Maria have. The second line contains nintegers ai (1 ≤ ai ≤ 100)
— the number of cookies in the i-th bag.

Output

Print in the only line the only number — the sought number of ways. If there are no such ways print 0.

Sample test(s)

input

1
1

output

1

input

10
1 2 2 3 4 4 4 2 2 2

output

8

input

11
2 2 2 2 2 2 2 2 2 2 99

output

1

题意：从一个数列中任取出一个数，使剩下的数的和是偶数，问共同拥有多少种取法。

O（n*n）算法 ，非常暴力。

。

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <string>
#include <vector>
using namespace std;
#define LL long long
int main()
{
	int a[110],i,j,n,sum;
	while(scanf("%d",&n)!=EOF)
	{
		int cnt=0;
		for(i=0;i<n;i++)
			scanf("%d",a+i);
		for(i=0;i<n;i++)
		{
			sum=0;
			for(j=0;j<n;j++)
				if(j!=i)
					sum+=a[j];
			if(sum%2==0)
				cnt++;
		}
		printf("%d\n",cnt);
	}
	return 0;
}