模拟赛（11.4）

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cmath>
#include<cstring>
#include<algorithm>
using namespace std;
int main()
{
    freopen("block.in","r",stdin);
    freopen("block.out","w",stdout);
    int T;
    scanf("%d",&T);
    while(T--)
    {
        long long n,ans=-1;
        scanf("%lld",&n);
        long long i=sqrt(n);
        for(long long j=i;j>=1;j--)
        {
            long long tmp=2*(i+(n/i));
            if(n%i) tmp+=2;
            if(ans==-1)ans=tmp;
            else ans=min(ans,tmp);
        }
        printf("%lld
",ans);
    }        
}

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cmath>
#include<cstring>
#include<algorithm>
using namespace std;
struct data
{
    long long v;
    int x,y;
    bool operator < (const data &a)const
    {
        return v<a.v;
    }
}e[20010];
int fa[20010];
int weight[20010];
int find(int x) {return fa[x]==x?x:fa[x]=find(fa[x]);}
int main()
{
    freopen("tree.in","r",stdin);
    freopen("tree.out","w",stdout);
    int T;
    scanf("%d",&T);
    while(T--)
    {
        memset(e,0,sizeof(e));
        int n;
        scanf("%d",&n);
        for(int i=1;i<=n;i++){fa[i]=i;weight[i]=1;}
        for(int i=1;i<n;i++)
        {
            scanf("%d%d",&e[i].x,&e[i].y);
            scanf("%lld",&e[i].v);
        }
        sort(e+1,e+n);
        long long ans=0;
        for(int i=1;i<n;i++)
        {
            int x=find(e[i].x),y=find(e[i].y),val=e[i].v;
            ans+=(long long)(weight[x]*weight[y])*(long long)(val+1)-1;
            fa[x]=y;
            weight[y]+=weight[x];
        }
        printf("%lld
",ans);
    }        
}

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cmath>
#include<cstring>
#include<algorithm>
using namespace std;
struct data
{
    int a,b;
    bool operator <(const data &t) const
    {
        return a<t.a;
    }
    bool operator == (const data &t)const
    {
        return (a==t.a&&b==t.b);
    }    
}ans[200010],tmx[200010];
int nm[200010];
int lg[200010];
int f[2][25][200010];
int mi[30];
int n;
int mark[200010];
void work(int l,int r)
{
    if(l>r) return;
    if(l+1==r) {ans[r].a=nm[l];ans[r].b=nm[r];ans[l].a=nm[l];ans[l].b=nm[r];return;}
    int tmp=r-l+1;
    int min1=n+1,min2=n+1;
    int p1=l,p2=l;
    int fg=l%2;
    for(int i=lg[tmp];i>=0;i--)
    {
        if(mi[i]<=tmp)
        {
            tmp-=mi[i];
            min1=min(min1,f[fg][i][p1]);
            p1+=mi[i];
        }
    }
    fg^=1;
    p1=mark[min1];
    p2=p1+1;
    tmp=r-p2+1;
    for(int i=lg[tmp];i>=0;i--)
    {
        if(mi[i]<=tmp)
        {
            tmp-=mi[i];
            min2=min(min2,f[fg][i][p2]);
            p2+=mi[i];
        }
    }
    p2=mark[min2];
    work(l,p1-1);work(p1+1,p2-1);work(p2+1,r);
    int t1=l,t2=p1+1,t3=p2+1;
    int cnt=0;
    tmx[cnt].a=min1,tmx[cnt++].b=min2;
    tmx[cnt].a=min1,tmx[cnt++].b=min2;
    while(t1<=p1-1||t2<=p2-1||t3<=r)
    {
        data anss;anss.a=anss.b=n+1;
        if(t1<=p1-1) anss=min(anss,ans[t1]);
        if(t2<=p2-1) anss=min(anss,ans[t2]);
        if(t3<=r) anss=min(anss,ans[t3]);
        if(anss==ans[t1]) tmx[cnt++]=ans[t1++];
        else if(anss==ans[t2]) tmx[cnt++]=ans[t2++];
        else tmx[cnt++]=ans[t3++];
    }
    for(int i=0;i<cnt;i++)
    {
        ans[i+l]=tmx[i];
    }
}
int main()
{
    freopen("ball.in","r",stdin);
    freopen("ball.out","w",stdout);
    mi[0]=1;for(int i=1;i<25;i++) mi[i]=mi[i-1]*2;
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
        lg[i]=mi[lg[i-1]]*2>=n?lg[i-1]:lg[i-1]+1;
        scanf("%d",&nm[i]);
        mark[nm[i]]=i;
        f[i%2][0][i]=nm[i];
        f[(i+1)%2][0][i]=n+1;
    }
    for(int i=1;i<=lg[n];i++)
    {
        for(int j=1;j<=n;j++)
        {
            if(j+mi[i]-1<=n)
            {
                f[0][i][j]=min(f[0][i-1][j],f[0][i-1][j+mi[i-1]]);
                f[1][i][j]=min(f[1][i-1][j],f[1][i-1][j+mi[i-1]]);
            }
        }
    }
    work(1,n);
    for(int i=1;i<=n;i+=2)
    {
        printf("%d %d ",ans[i].a,ans[i].b);
    }
}