【HDU5306】【DTOJ2481】Gorgeous Sequence【线段树】

待填坑

代码：

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<string>
#define ll long long
using namespace std;
int T,n,m;
ll a[1000001];
class Segtree
{
public:
    ll sum[1000001*5],mx[1000001*5],smx[1000001*5],cnt[1000001*5],fl[1000001*5];

    void pushup(int pos)
    {
        sum[pos]=sum[pos<<1]+sum[pos<<1|1];
        if(mx[pos<<1]>mx[pos<<1|1])
        {
          mx[pos]=mx[pos<<1];
          cnt[pos]=cnt[pos<<1];
          if(mx[pos<<1|1]>smx[pos<<1])smx[pos]=mx[pos<<1|1];
          else smx[pos]=smx[pos<<1];
        }
        if(mx[pos<<1]<mx[pos<<1|1])
        {
          mx[pos]=mx[pos<<1|1];
          cnt[pos]=cnt[pos<<1|1];
          if(mx[pos<<1]>smx[pos<<1|1])smx[pos]=mx[pos<<1];
          else smx[pos]=smx[pos<<1|1];
        }
        if(mx[pos<<1]==mx[pos<<1|1])
        {
          mx[pos]=mx[pos<<1];
          cnt[pos]=cnt[pos<<1]+cnt[pos<<1|1];
          if(smx[pos<<1]>smx[pos<<1|1])smx[pos]=smx[pos<<1];
          else smx[pos]=smx[pos<<1|1];
        }
    }
    void pushdown(int pos)
    {
        if(fl[pos]>=0)
        {
          if(mx[pos<<1]>fl[pos])
          {
            sum[pos<<1]-=(mx[pos<<1]-fl[pos])*cnt[pos<<1];
            fl[pos<<1]=mx[pos<<1]=fl[pos];
          }
          if(mx[pos<<1|1]>fl[pos])
          {
            sum[pos<<1|1]-=(mx[pos<<1|1]-fl[pos])*cnt[pos<<1|1];
            fl[pos<<1|1]=mx[pos<<1|1]=fl[pos];
          }
          fl[pos]=-1;
        }
    }
    void build(int l,int r,int pos)
    {
        if(l==r)
        {
          sum[pos]=mx[pos]=a[l];
          cnt[pos]=1;
          fl[pos]=smx[pos]=-1;
          return;
        }
        int mid=l+r>>1;
        build(l,mid,pos<<1);
        build(mid+1,r,pos<<1|1);
        pushup(pos);
        fl[pos]=-1;
    }
    void change(int l,int r,int al,int ar,ll v,int pos)
    {
        int mid=l+r>>1;
        if(l==al && r==ar)
        {
          if(v>=mx[pos])return;
          if(smx[pos]<v && v<mx[pos])
          {
              sum[pos]-=(mx[pos]-v)*cnt[pos];
              fl[pos]=mx[pos]=v;
              return;
          }
          change(l,mid,al,mid,v,pos<<1);
          change(mid+1,r,mid+1,ar,v,pos<<1|1);
          pushup(pos);
          return;
        }
        pushdown(pos);
        if(ar<=mid)change(l,mid,al,ar,v,pos<<1);
        if(al>mid)change(mid+1,r,al,ar,v,pos<<1|1);
        if(al<=mid && ar>mid){change(l,mid,al,mid,v,pos<<1);change(mid+1,r,mid+1,ar,v,pos<<1|1);}
        pushup(pos);
    }
    ll askmax(int l,int r,int al,int ar,int pos)
    {
        if(l==al && r==ar)return mx[pos];
        int mid=l+r>>1;
        pushdown(pos);
        if(ar<=mid)return askmax(l,mid,al,ar,pos<<1);
        if(al>mid)return askmax(mid+1,r,al,ar,pos<<1|1);
        if(al<=mid && ar>mid)
        {
          ll t1=askmax(l,mid,al,mid,pos<<1),t2=askmax(mid+1,r,mid+1,ar,pos<<1|1);
          return t1>t2?t1:t2;
        }
    }
    ll asksum(int l,int r,int al,int ar,int pos)
    {
        if(l==al && r==ar)return sum[pos];
        int mid=l+r>>1;
        pushdown(pos);
        if(ar<=mid)return asksum(l,mid,al,ar,pos<<1);
        if(al>mid)return asksum(mid+1,r,al,ar,pos<<1|1);
        if(al<=mid && ar>mid)return asksum(l,mid,al,mid,pos<<1)+asksum(mid+1,r,mid+1,ar,pos<<1|1);
    }
}segtree;
int main()
{
    scanf("%d",&T);
    while(T--)
    {
      scanf("%d%d",&n,&m);
      for(int i=1;i<=n;i++)scanf("%lld",&a[i]);
      segtree.build(1,n,1);
      int mod,x,y;ll t;
      while(m--)
      {
        scanf("%d",&mod);
        if(mod==0)
        {
          scanf("%d%d%lld",&x,&y,&t);
          segtree.change(1,n,x,y,t,1);
        }
        if(mod==1)
        {
          scanf("%d%d",&x,&y);
          printf("%lld\n",segtree.askmax(1,n,x,y,1));
        }
        if(mod==2)
        {
          scanf("%d%d",&x,&y);
          printf("%lld\n",segtree.asksum(1,n,x,y,1));
        }
      }
    }
    return 0;
}

原文地址：https://www.cnblogs.com/worcher/p/11561073.html