bzoj2321 星器

定义一个点的势能是i²+j²，求出两个状态的势能之差。。。

我不会证明。

#include <math.h>
#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std;

#define g() getchar()
template<class Q>void Scan(Q&x){
	char c;int f=1;
	while(c=g(),c<48||c>57)if(c=='-')f=-1;
	for(x=0;c>47&&c<58;c=g())x=10*x+c-48;
	x*=f;
}

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define inf 0x7f7f7f7f
#define Max(x,y) if(x<y)x=y
#define Min(x,y) if(x>y)x=y
#define rep(i,a,b) for(int i=a;i<b;++i)
typedef long long ll;
typedef double db;

int n,m; 

ll ans;

int main(){
	Scan(n),Scan(m);
	rep(i,1,n+1)
		rep(j,1,m+1){
			int x; Scan(x);
			ans+=(1ll*i*i+1ll*j*j)*x; 
		} 
	rep(i,1,n+1)
		rep(j,1,m+1){
			int x; Scan(x);
			ans-=(1ll*i*i+1ll*j*j)*x; 
		} 	
	if(ans<0)ans=-ans;
	printf("%lld\n",ans>>1);
	return 0;
}