[CSP-J 2023] 小苹果

#include <bits/stdc++.h>
using namespace std;
int n,ans=0,ans2=0;
bool flag=true;
int main()
{
    freopen("apple.in","r",stdin);
    freopen("apple.out","w",stdout);
    cin >> n;
    while(n)
    {
        ans++;
        if(flag&&n%3==1) 
        {
            flag=false;
            ans2=ans;
        }
        n=n-ceil(n/3.0);
    }
    cout << ans << " " << ans2;
    return 0;
}

[CSP-J 2023] 公路

#include <bits/stdc++.h>
using namespace std;
long long n,d;
long long v[100001],a[100001],s[100001];
int main()
{
    freopen("road.in","r",stdin);
    freopen("road.out","w",stdout);
    cin >> n >> d;
    for(int i=1;i<n;i++)
    {
        cin >> v[i];
        s[i+1]=s[i]+v[i];
    }
    for(int i=1;i<=n;i++) cin >> a[i];
    long long now=1,lc=0,spend=0;
    for(int i=2;i<n;i++)
    {
        if(a[i] < a[now])
        {
            long long hs=(long long)(ceil((s[i]-lc)*1.0/d));
            lc += hs*d;
            spend+=hs*a[now];
            now=i;
        }
    }
    if(lc >= s[n]) 
    {
        cout << spend;
        return 0;
    }
    else 
    {
        spend += (long long)(ceil((s[n]-lc)*1.0/d))*a[now];
        cout << spend;
    }
    return 0;
}

[CSP-J 2023] 一元二次方程

#include <bits/stdc++.h>
using namespace std;
int t,m;
int gcd(int a,int b)
{
    if(b == 0) return a;
    int r=a%b;
    return gcd(b,r);
}
void print(int fz,int fm)
{
    int k=gcd(fz,fm);
    fz /= k;fm /= k;
    if(fm < 0)
    {
        fm *= -1;
        fz *= -1;
    }
    if(fm == 1) cout << fz;
    else cout << fz << "/" << fm;
}
void solve()
{
    int a,b,c;
    cin >> a >> b >> c;
    int delta=b*b-4*a*c;
    if(delta < 0) 
    {
        cout << "NO" << endl;
        return ;
    }
    int g=0,r;
    for(int i=sqrt(delta);i>=1;i--)
    {
        if(delta % (i*i) == 0) 
        {
            g=i;
            r=delta/(i*i);
            break;
        }
    }
    if(g*g == delta)
    {
        int fz,fm;
        if(a > 0)
        {
            fz=-b+g;fm=2*a;
            print(fz,fm);
        }
        else
        {
            fz=-b-g;fm=2*a;
            print(fz,fm);
        }
        cout << endl;
        return ;
    }
    else
    {
        if(b != 0)
        {
            int fz=-b,fm=2*a;
            print(fz,fm);
            cout << "+";
        }
        int fz,fm,k;
        if(a > 0)
        {
            fz=g,fm=2*a;
            k=gcd(fz,fm);
            fz/=k;fm/=k;
        }
        else
        {
            fz=-g,fm=2*a;
            k=gcd(fz,fm);
            fz/=k;fm/=k;
        }
        if(fz == 1&&fm == 1) cout << "sqrt(" << r << ")" << endl;
        else if(fm == 1) cout << fz << "*sqrt(" << r << ")" << endl;
        else if(fz == 1) cout << "sqrt(" << r << ")/"<< fm << endl;
        else cout << fz << "*sqrt(" << r << ")/" << fm << endl;
    }
}
int main()
{
    freopen("uqe.in","r",stdin);
    freopen("uqe.out","w",stdout);
    cin >> t >> m;
    while(t--) solve();
    return 0;
}

[CSP-J 2023] 旅游巴士

#include <bits/stdc++.h>
#define inf 1e9
using namespace std;
int n,m,k;
struct node
{
    int v,a;
};
vector<node> arr[1000001]; 
struct node2
{
    int id,t;
    bool operator < (const node2&a) const
    {
        return t > a.t;
    }
};
int dist[1000001],vis[1000001];
priority_queue<node2> que;
void Dijkstra()
{
    fill(dist,dist+1000000,inf);
    que.push({1,0});
    dist[1]=0;
    while(!que.empty())
    {
        node2 top=que.top();
        que.pop();
        if(vis[top.id] == 1||dist[top.id] < top.t) continue;
        vis[top.id]=1;
        for(int i=0;i<arr[top.id].size();i++)
        {
            int j=arr[top.id][i].v,w=arr[top.id][i].a,t=dist[top.id];
            while(t < w) t+=k;
            t++;
            if(t < dist[j]) 
            {
                dist[j]=t;
                que.push({j,dist[j]});
            }
        }
    }
    if(dist[n] == inf) cout << -1;
    else cout << dist[n];
}
int main()
{
    freopen("bus.in","r",stdin);
    freopen("bus.out","w",stdout);
    cin >> n >> m >> k;
    int u,v,a;
    for(int i=1;i<=m;i++)
    {
        cin >> u >> v >> a;
        for(int j=0;j<k;j++)
        {
            //建立分层图 
            arr[j*n+u].push_back({((j+1)%k)*n+v,a});
        }
    }
    Dijkstra();
    return 0;
}