View Compilation Error

0_0_17914160_1202.cpp: In function 'int main()':
0_0_17914160_1202.cpp:50:40: error: 'memset' was not declared in this scope
          memset(weight,0,sizeof(weight));
                                        ^
0_0_17914160_1202.cpp:62:38: error: 'sort' was not declared in this scope
          sort(weight+1,weight+m+1,cmp);
                                      ^