/in/foo.cc: In function 'int main()':
/in/foo.cc:10:16: error: 'n' was not declared in this scope
  scanf("%d%d",&n,&m);
                ^
/in/foo.cc:13:18: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   for(int j=1;j<=m;j++)
                  ^
/in/foo.cc:15:16: error: 'x' was not declared in this scope
    scanf("%d",&x);
                ^
/in/foo.cc:18:5: error: 'd' was not declared in this scope
     d[i][j]=m(d[i-1][j],m(d[i][j-1],f[i-1][j-1]))
     ^
/in/foo.cc:18:37: error: 'f' was not declared in this scope
     d[i][j]=m(d[i-1][j],m(d[i][j-1],f[i-1][j-1]))
                                     ^
/in/foo.cc:23:5: error: 'f' was not declared in this scope
     f[i][j]=0;
     ^
/in/foo.cc:25:4: error: 'ans' was not declared in this scope
    ans=max(ans,f[i][j]);//调用max函数组
    ^~~
/in/foo.cc:25:16: error: 'f' was not declared in this scope
    ans=max(ans,f[i][j]);//调用max函数组
                ^
/in/foo.cc:28:15: error: 'an' was not declared in this scope
   printf("%d",an);
               ^~