View Compilation Error

0_0_38628741_15281.cpp: In function 'int main()':
0_0_38628741_15281.cpp:37:16: error: 'np' was not declared in this scope
         memset(np,0,sizeof mp);
                ^~
0_0_38628741_15281.cpp:37:16: note: suggested alternative: 'n'
         memset(np,0,sizeof mp);
                ^~
                n