View Compilation Error

0_0_17021771_19587.cpp: In function 'int main()':
0_0_17021771_19587.cpp:50:39: error: 'memset' was not declared in this scope
         memset(weight,0,sizeof(weight));
                                       ^
0_0_17021771_19587.cpp:62:37: error: 'sort' was not declared in this scope
         sort(weight+1,weight+m+1,cmp);
                                     ^