camp训练day2

https://vjudge.net/contest/313217

喔要补完题！！

A

#include<bits/stdc++.h>
using namespace std;
const int mod=1e9+7;
#define ll long long
const int maxn=1e6+10;
ll f[maxn][2];
int main()
{
    freopen("azerah.in","r",stdin);
    freopen("azerah.out","w",stdout);
    int t;
    scanf("%d",&t);
    while(t--)
    {
        int n;
        scanf("%d",&n);
        for(int i=1; i<=n; i++)
        {
            int a;
            scanf("%d",&a);
            f[i][0]=f[i][1]=0;
            if(a%2==0)
            {
                f[i][0]=(f[i-1][0]*2)%mod;
                f[i][1]=(f[i-1][1]*2)%mod;
                f[i][0]=(f[i][0]+1)%mod;
            }
            else
            {
                f[i][0]=(f[i-1][0]+f[i-1][1])%mod;
                f[i][1]=(f[i-1][1]+f[i-1][0])%mod;
                f[i][1]=(f[i][1]+1)%mod;
            }
//            printf("%d %d
",f[i][0],f[i][1]);
        }
        printf("%lld
",f[n][0]%mod);
    }
    return 0;
}

B

C

D

E

F

G

H

I

#include<bits/stdc++.h>
using namespace std;
//const int maxn=1e7+10;
#define ll long long
//map<ll,ll> m;

ll fun(ll n)
{
    ll ans=0;
    int i;
    for(i=1; i<=(int)sqrt(n); i++)
        ans=ans+n/i;
    i--;
    ans=ans*2;
    ans=ans-i*i;
    return ans;
}
int main()
{
    freopen("perechi3.in","r",stdin);
    freopen("perechi3.out","w",stdout);
    int t;
    scanf("%d",&t);
    while(t--)
    {
        ll n;
        scanf("%lld",&n);
        ll ans=fun(n);
        printf("%lld
",ans);
    }

}

J

K

L

#include<bits/stdc++.h>
using namespace std;
#define ll long long
int main()
{
    freopen("semipal.in","r",stdin);
    freopen("semipal.out","w",stdout);
    int t;
    scanf("%d",&t);
    while(t--)
    {
        int n;
        ll k;
        string s;
        scanf("%d%lld",&n,&k);
        k--;
        for(int i=n-1;i>=1;i--)
        {
            if((k>>(i-1))&1)
                s+='b';
            else
                s+='a';
        }
        s+=s[0];
        cout<<s<<endl;
    }
}