Gym 101606

链接：https://codeforces.com/gym/101606

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A - Alien Sunset

暴力枚举小时即可。

#include<bits/stdc++.h>
using namespace std;
const int maxn=23;
int n;
int h[maxn],r[maxn],s[maxn];
inline bool dark(int id,int time)
{
    if(r[id]<s[id])
    {
        if(r[id]<time && time<s[id]) return 0;
        else return 1;
    }
    if(r[id]>s[id])
    {
        if(s[id]<=time && time<=r[id]) return 1;
        else return 0;
    }
}
int main()
{
    cin>>n;
    int mx=0;
    for(int i=1;i<=n;i++) cin>>h[i]>>r[i]>>s[i], mx=max(h[i],mx);

    for(int time=0;time<mx*1825;time++)
    {
        bool ok=1;
        for(int i=1;i<=n;i++) if(!dark(i,time%h[i])) ok=0;
        if(ok)
        {
            cout<<time<<endl;
            return 0;
        }
    }
    cout<<"impossible"<<endl;
}

---

B - Breaking Biscuits - (Undone)

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C - Cued In - [水]

#include<bits/stdc++.h>
using namespace std;
int n;
string s;
map<string,int> mp;
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);

    mp["red"]=1,
    mp["yellow"]=2,
    mp["green"]=3,
    mp["brown"]=4,
    mp["blue"]=5,
    mp["pink"]=6,
    mp["black"]=7;

    cin>>n;
    int red=0, sum=0, mx=0;
    for(int i=1;i<=n;i++)
    {
        cin>>s;
        mx=max(mx,mp[s]);
        if(s=="red") red++;
        else sum+=mp[s];
    }

    if(red==n) cout<<"1
";
    else if(red==0) cout<<sum<<'
';
    else cout<<red*(mx+1)+sum<<'
';
}

---

D - Deranging Hat - (Undone)

---

E - Education - [贪心]

$O(n^2)$ 时间复杂度的贪心。

#include<bits/stdc++.h>
using namespace std;
typedef pair<int,int> P;
#define fi first
#define se second
const int maxn=5e3+10;

int n,m;
P s[maxn];
int ans[maxn];

struct F{
    int id;
    int capa,rent;
    bool operator<(const F& o)
    {
        return capa>o.capa;
    }
}f[maxn];
bool vis[maxn];

int main()
{
    cin>>n>>m;
    for(int i=1;i<=n;i++) scanf("%d",&s[i].fi), s[i].se=i;
    sort(s+1,s+n+1,greater<P>{});

    //for(int i=1;i<=n;i++) printf("%d %d
",s[i].fi,s[i].se);

    for(int i=1;i<=m;i++) f[i].id=i;
    for(int i=1;i<=m;i++) scanf("%d",&f[i].capa);
    for(int i=1;i<=m;i++) scanf("%d",&f[i].rent);
    sort(f+1,f+m+1);

    //for(int i=1;i<=m;i++) printf("%d: %d %d
",f[i].id,f[i].capa,f[i].rent);

    memset(vis,0,sizeof(vis));
    memset(ans,0,sizeof(ans));
    for(int i=1;i<=n;i++)
    {
        int mn=1e3+50, mnid=0;
        for(int j=1;j<=m && f[j].capa>=s[i].fi;j++)
        {
            if(vis[j]) continue;
            if(f[j].rent<mn)
            {
                mn=f[j].rent;
                mnid=j;
            }
        }
        vis[mnid]=1;
        ans[s[i].se]=f[mnid].id;
    }
    bool ok=1;
    for(int i=1;i<=n;i++) if(ans[i]==0) ok=0;
    if(ok) for(int i=1;i<=n;i++) printf("%d ",ans[i]);
    else printf("impossible");
    cout<<endl;
}

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F - Flipping Coins - [概率DP]

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H - Hiking - (Undone)

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I - I Work All Day - (Undone)

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J - Just A Minim - [水]

#include<bits/stdc++.h>
using namespace std;
int n;
double t[20];
int main()
{
    t[0]=2.0;
    t[1]=1.0;
    t[2]=1.0/2.0;
    t[4]=1.0/4.0;
    t[8]=1.0/8.0;
    t[16]=1.0/16.0;

    cin>>n;
    double res=0.0;
    for(int i=1,x;i<=n;i++)
    {
        scanf("%d",&x);
        res+=t[x];
    }
    printf("%.7f
",res);
}

---

L - Lizard Lounge - [计算几何+LIS]