386B Codeforces - Sereja and suffixes

386B Codeforces - Sereja and suffixes

Link ; http://codeforces.com/problemset/problem/368/B

Solution in C++

#include <bits/stdc++.h>

using namespace std;

#define pii pair<int,int>

typedef long long int lli;

lli n,m,t;

map<lli,lli> all,occ;

int main()

{

    ios::sync_with_stdio(0);

    cin.tie(0);cout.tie(0);

    cin>>n>>m;

    int arr[n];

    for(int i=0;i<n;i++)cin>>arr[i];

    for(int i=n-1;i>=0;i--)

    {

        if(occ[ arr[i] ])all[i]+=all[i+1];

        else

            all[i]=all[i+1]+1,

            occ[ arr[i] ]=1;

    }

    while(m--)cin>>t,cout<<all[t-1]<<"\n";

    return 0;

}

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About Mohamed Sobhi

My name is Mo.Sobhy ,I study at School excelling high school in Ain Shams ,Cairo
My hobbies is programming ,and web development ,playing chess and writing horror stories.