#include<iostream>
#include<string.h>
#include<stdio.h>
using namespace std;
long int c[1000005],n;
long int a[1000005];
int lowbit(int x)
{
    return x&(-x);
}
int sum(int x)
{
    int s=0;
    while(x>0)
    {
        s+=c[x];
        x-=lowbit(x);
    }
    return s;
}
void add(int x, int add)
 {
    while(x<=n)
    {
        c[x]+=add;   
        x+=lowbit(x);
    }
}
int main()
{
    int t,p,k,sumc,y,cc,i,q=1;
    cin>>t;
    while(t--)
   {
        cin>>n>>p>>k;
        memset(c,0,sizeof(c));
        for(i=1;i<=n;i++)
        {
            scanf("%ld",&a[i]);
            add(i,a[i]);
        }
        cout<<"Case "<<q++<<": ";
        sumc=sum(n);
        cc=sumc/p;
        y=sumc%p;
        if(y>=k)
            cout<<"-1"<<endl;
        else
            cout<<cc<<endl;
    }
    return 0;
}

我这用的树状数组做的，应该不是超时呀！

好吧！我尝试用线段树做！