ArcSoft's Office Rearrangement---hdu5933

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=5933

题意：给你一个数组含有n个数，然后把这些数分为k份，每份都相等；有两个操作：合并相邻的两个数；把一个数分为两个数；

求最少的操作次数;

#include<stdio.h>
#include<string.h>
#include<iostream>
#include<vector>

using namespace std;
typedef long long LL;
const int N = 100615;

LL a[N];
int n, k;

int main()
{
    int T, t = 1;
    scanf("%d", &T);
    while(T --)
    {
        scanf("%d %d", &n, &k);

        LL sum = 0;

        for(int i=1; i<=n; i++)
        {
            scanf("%I64d", &a[i]);
            sum += a[i];
        }

        if(sum%k)
        {
            printf("Case #%d: -1
", t++);
            continue;
        }

        LL num = sum/k, ans = 0, r = 0;

        for(int i=1; i<=n; i++)
        {
            if(r)
                ans ++;
            if((a[i]+r)%num == 0)
                ans += (a[i]+r)/num - 1;
            else
                ans += (a[i]+r)/num;
            r = (a[i]+r)%num;
        }
        printf("Case #%d: %I64d
", t++, ans);
    }
    return 0;
}