cf B Three matrices

 #include <cstdio>
 #include <cstring>
 #include <algorithm>
 using namespace std;

 int g[][];
 int n;

 int main()
 {
      while(scanf("%d",&n)!=EOF)
      {
          for(int i=; i<=n; i++)
          {
              for(int j=; j<=n; j++)
              {
                  scanf("%d",&g[i][j]);
              }
          }
          for(int i=; i<=n; i++)
          {
              for(int j=; j<=n; j++)
              {
                  if(i==j)
                  {
                      printf("%.8lf ",(double)g[i][j]);
                  }
                  else
                  {
                      printf("%.8lf ",(double)((g[i][j]+g[j][i])*1.0/));
                  }
              }
              printf("\n");
          }
          for(int i=; i<=n; i++)
          {
              for(int j=; j<=n; j++)
              {
                  if(i==j) printf("%.8lf ",(double));
                  else
                  {
                      printf("%.8lf ",(double)((double)g[i][j]-(g[i][j]+g[j][i])*1.0/));
                  }
              }
              printf("\n");
          }
      }
      return ;
 }