A - Kyu in AtCoder

直接模拟

#define IO ios::sync_with_stdio(false);cin.tie();cout.tie(0)
#define debug(x) cout<<#x<<": "<<x<<" "
#include<iostream>
#include<algorithm>
using namespace std;
int main()
{IO;int x;cin>>x;//cout<<10-x/200<<endl;标准答案if(x<=599)       cout<<'8'<<endl;else if(x<=799)  cout<<'7'<<endl;else if(x<=999)  cout<<'6'<<endl;else if(x<=1199) cout<<'5'<<endl;else if(x<=1399) cout<<'4'<<endl;else if(x<=1599) cout<<'3'<<endl;else if(x<=1799) cout<<'2'<<endl;else cout<<'1'<<endl;return 0;
}

B - Magic 2

贪心

#define IO ios::sync_with_stdio(false);cin.tie();cout.tie(0)
#define debug(x) cout<<#x<<": "<<x<<" "
#include<iostream>
#include<algorithm>
using namespace std;
int main()
{IO;int a,b,c,k;cin>>a>>b>>c>>k;int cnt=0;while(b<=a){b*=2;cnt++;}while(c<=b){c*=2;cnt++;}if(cnt<=k) cout<<"Yes"<<endl;else cout<<"No"<<endl;return 0;
}

C - Marks

比较一下就可以了

#define IO ios::sync_with_stdio(false);cin.tie();cout.tie(0)
#define debug(x) cout<<#x<<": "<<x<<" "
#include<iostream>
#include<algorithm>
using namespace std;
const int N=200010;
int a[N];
int main()
{IO;int n,k;cin>>n>>k;for(int i=1;i<=n;i++) cin>>a[i];for(int i=k+1;i<=n;i++){if(a[i]>a[i-k]) cout<<"Yes"<<endl;else cout<<"No"<<endl;}return 0;
}

D - Road to Millionaire

贪心：有钱就赚，低买高卖

#define IO ios::sync_with_stdio(false);cin.tie();cout.tie(0)
#define debug(x) cout<<#x<<": "<<x<<" "
#include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;
const int N=100;
int a[N],n;
int main()
{IO;cin>>n;for(int i=1;i<=n;i++) cin>>a[i];ll res=1000;for(int i=1;i<=n;i++)if(i<=n&&a[i+1]>=a[i])res=res/a[i]*a[i+1]+res%a[i];cout<<res<<endl;return 0;
}

只能做这些容易题~~嗨，要加油哦！