BZOJ 1045 [HAOI2008] 糖果传递

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cmath>
 4 #include<algorithm>
 5 #include<stack>
 6 #include<queue>
 7 #include<cstring>
 8 #define PAU putchar(‘ ‘)
 9 #define ENT putchar(‘\n‘)
10 using namespace std;
11 const int maxn=1000000+10;
12 int A[maxn],p[maxn],n;
13 long long ans,tot,pos;
14 inline int read(){
15     int x=0,sig=1;char ch=getchar();
16     for(;!isdigit(ch);ch=getchar())if(ch==‘-‘)sig=0;
17     for(;isdigit(ch);ch=getchar())x=10*x+ch-‘0‘;
18     return sig?x:-x;
19 }
20 inline void write(long long  x){
21     if(x==0){putchar(‘0‘);return;}if(x<0)putchar(‘-‘),x=-x;
22     int len=0;long long buf[20];while(x)buf[len++]=x%10,x/=10;
23     for(int i=len-1;i>=0;i--)putchar(buf[i]+‘0‘);return;
24 }
25 int main(){
26     n=read();for(int i=0;i<n;i++)A[i]=read(),tot+=A[i];
27     tot/=n;for(int i=1;i<n;i++)p[i]=p[~-i]+tot-A[i];
28     sort(p,p+n);pos=p[n>>1];
29     for(int i=0;i<n;i++)ans+=abs(p[i]-pos);write(ans);
30     return 0;
31 }