I tried to solve this question but suddenly a question strike to my mind what if we have to find the value of ONLY F(L,R,X) L and R are the indexes of the array and X=The element whose frequency we have to determined . one solution which strike to me is like..just take map< long long,vector >mp,and for each element of the given array just insert its corresponding index at that location for example if arr[]=[2,3,4,5,2,2].So mp[2]={0,5,6},mp[3]={3},mp[4]={2} and so on... and just take lower bound and upper bound of the value of L and R in mp[x]. So it will give us answer in NO of Query * O(log(abs(R-L)).

But Can some one please suggest me how can i can calculate ONLY F(L,R,X) by using SEGMENT TREE Proble Link.....

Thanks In Advance..!!