bzoj2396 神奇的矩阵

#include<bits/stdc++.h>
using namespace std;
int A[1005][1005],B[1005][1005],C[1005][1005];
int f[1005],fx[1005],fy[1005];
int n,flg;
inline char nc()
{
static char buf[100000],*p1=buf,*p2=buf;
return p1==p2&&(p2=(p1=buf)+fread(buf,1,100000,stdin),p1==p2)?EOF:*p1++;
}
inline int read()
{
int x=0,b=1;
char c=nc();
for(;!(c<='9'&&c>='0');c=nc())if(c=='-')b=-1;
for(;c<='9'&&c>='0';c=nc())x=x*10+c-'0';
return x*b;
}
inline void write(int x)
{
if(x==0)putchar('0');
else
{
char buf[15];
int len=0;
if(x<0)putchar('-'),x=-x;
while(x)buf[++len]=x%10+'0',x/=10;
for(int i=len;i>=1;i--)putchar(buf[i]);
}
putchar(' ');
}
int main()
{
freopen("in.txt","r",stdin);
while(scanf("%d",&n)!=EOF)
{
memset(f,0,sizeof(f));
memset(fx,0,sizeof(fx));
memset(fy,0,sizeof(fy));
srand(n*n+2*n+1+10);
for(int i=1;i<=n;i++)
for(int j=1;j<=n;j++)
scanf("%d",&A[i][j]);
for(int i=1;i<=n;i++)
for(int j=1;j<=n;j++)
scanf("%d",&B[i][j]);
for(int i=1;i<=n;i++)
for(int j=1;j<=n;j++)
scanf("%d",&C[i][j]);
for(int i=1;i<=n;i++)f[i]=rand()%10+1;
for(int i=1;i<=n;i++)
for(int j=1;j<=n;j++)
fx[i]+=A[j][i]*f[j];
memcpy(fy,fx,sizeof(fx));
memset(fx,0,sizeof(fx));
for(int i=1;i<=n;i++)
for(int j=1;j<=n;j++)
fx[i]+=B[j][i]*fy[j];
memset(fy,0,sizeof(fy));
for(int i=1;i<=n;i++)
for(int j=1;j<=n;j++)
fy[i]+=C[j][i]*f[j];
flg=true;
for(int i=1;i<=n;i++)if(fx[i]!=fy[i])flg=false;
if(flg)puts("Yes");
else puts("No");
}
return 0;
}