foo.cc: In function 'int main()':
foo.cc:8:25: error: 'memset' was not declared in this scope
  memset(a,0x00,sizeof(a));
                         ^
foo.cc:13:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(int i=1;i<=9;i++)
  ^~~
foo.cc:16:3: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
   for(int i=1;i<=9;i++)
   ^~~
foo.cc:42:21: warning: for increment expression has no effect [-Wunused-value]
   for(int i=1;i+=3;i<=7)
                    ~^~~
foo.cc:44:22: warning: for increment expression has no effect [-Wunused-value]
    for(int j=1;j+=3;j<=7)
                     ~^~~
foo.cc:47:5: error: expected ';' before 'mul'
     mul*=a[i][j]*a[i+1][j]*a[i+2][j]*a[i][j+1]*a[i+1][j+1]*a[i+2][j+1]*a[i+2][j]*a[i+2][j+1]*a[i+2][j+2]
     ^~~

自豪的采用jd5进行评测(github.com/masnn/jd5)