View Compilation Error

1_867_5280_13648.cpp: In function 'int main()':
1_867_5280_13648.cpp:22:37: error: 'memset' was not declared in this scope
         memset(vis,false,sizeof(vis));
                                     ^
1_867_5280_13648.cpp:28:27: error: 'sort' was not declared in this scope
         sort(k+1,k+n+1,cmp);
                           ^