ABC340(A-C)

A

#include<bits/stdc++.h>
using namespace std;
int main()
{
  int a,b,d;
  cin>>a>>b>>d;
  while(a<=b){
    cout<<a<<" ";
    a+=d;
  }
  return 0;
}

B

#include<bits/stdc++.h>
using namespace std;
vector<int> v;
int main()
{
  int n;
  int a,b;
  cin>>n;
  while(n--){
    cin>>a>>b;
    if(a==1)v.push_back(b);
    else cout<<v[v.size()-b]<<endl;
  }
  return 0;
}

C

#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll n;
map<ll,ll> mp;
ll dfs(ll n){
    if(n<2)return 0;
    else{
        if(!mp[n]){
            long long tmp1 = dfs(n / 2), tmp2 = dfs(n - n / 2);
            if(n%2==0)mp[n]=tmp1*2+n;
            else mp[n]=tmp1+tmp2+n;
        }
        return mp[n];
    }
}
int main()
{
    cin>>n;
    cout<<dfs(n)<<endl;
    return 0;
}

记忆化搜索：dp+dfs