acmore 1510: ZZ love Cookies

1510: ZZ love Cookies

Time Limit: 1 Sec  Memory Limit:
64 MB
Submit: 228  Solved: 139SubmitStatusWeb Board

Description

　　One day, ZZ came to visit her friend LL and DD and saw that they have many cookies. The cookies are distributed into bags, As there are many cookies, ZZ decided that it’s no big deal
if she steals a bag. However, she doesn’t want to her friends to quarrel because of nothing when they divide the cookies. That’s why ZZ wants to steal a bag with cookies so that the number of cookies in the remaining bags was even, that is, so that LL and
DD could evenly divide into two (even 0 remaining cookies will do, just as any other even number). How many ways there are to steal exactly one cookies 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 ≤ 1000) — the number of cookie bags Anna and Maria have. The second line contains n integers ai (1 ≤ ai ≤ 1000) — 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 Input11101 2 2 3 4 4 4 2 2 2Sample Output18HINTSource

2013ACM多校聯合(4)_NUN

解題思路：只要留下的餅乾總數為偶數即可，若餅乾總數為偶數，則可取走餅乾數為偶數的任一包裹，否則可取走餅乾數為奇數的任一包裹。

#include<stdio.h>int main(){    int sum,sum1,sum2;    int n;    int a[1002];    int i;    while(scanf("%d",&n)!=EOF)    {        sum=0;        sum1=0;        sum2=0;        int j=n;        for(i=0;i<n;i++)        {            scanf("%d",&a[i]);            sum+=a[i];      //統計總數            if(a[i]%2==0)   //統計餅乾為偶數個的包裹個數                sum1++;            else        //統計餅乾為奇數個的包裹個數                sum2++;        }        if(sum%2==0)    //若總數為偶數，則可取走餅乾數為偶數的任意包裹            sum=sum1;        else                //若總數為奇數，則可取走餅乾數為奇數的任意包裹            sum=sum2;        printf("%d\n",sum);    }    return 0;}