/in/foo.cc:6:1: error: 'define' does not name a type
 define MAX 20
 ^~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:17:8: error: 'f' was not declared in this scope
 memset(f,0,sizeof(f));
        ^
/in/foo.cc: In function 'int Number(int, int)':
/in/foo.cc:32:1: error: 'f' was not declared in this scope
 f[i][0]=1;f[i][1]=1;//有一个盘子和没有有盘子的放法：1
 ^
/in/foo.cc:37:1: error: 'f' was not declared in this scope
 f[0][j]=1; f[1][j]=1;//有一个苹果和没有苹果的放法：1
 ^
/in/foo.cc:45:1: error: 'f' was not declared in this scope
 f[i][j]=f[i][j-1]+f[i-j][j];
 ^
/in/foo.cc:49:1: error: 'f' was not declared in this scope
 f[i][j]=f[i][i];
 ^
/in/foo.cc:52:8: error: 'f' was not declared in this scope
 return f[m][n];
        ^