#include
#include
#include
#include
#include
#include
#include

using?namespace?std;	///省略名為std的函數書寫?std::
const?int?Q=?9;			//D2Q9?model.?規則網格模型
const?int?NX=?256;		//x?方向
const?int?NY=?256;		//y?方向
const?double?U=?0.1;	//頂蓋速度
//c，網格步長，時間步長都為1
int?e[Q][2]=?{{00}{10}{01}{-10}{0-1}{11}{-11}{-1-1}{1-1}};			//根據模型進行速度配置，二維數組，每個點兩個方向，9行2列的數組。
double?w[Q]=?{4.0/91.0/91.0/91.0/91.0/91.0/361.0/361.0/361.0/36};
double?rho[NX+1][NY+1]u[NX+1][NY+1][2]u0[NX+1][NY+1][2]f[NX+1][NY+1][Q]F[NX+1][NY+1][Q];		//網格為256×256，節點數為257*257.
int?ijkipjpn;
double?cRedxdyLxLydtrho0P0tau_fniuerror;

void?init（）;
double?feq（int?kdouble?rhodouble?u[2]）;
void?evolution（）;
void?output（int?m）;