SKYLINE UVALive - 4108

https://icpcarchive.ecs.baylor.edu/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=2109

本来以为有什么高深的做法.. 试了一发暴力剪枝就过了..

维护区间最大最小值即可

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define N 0x3f3f3f3f

struct node1
{
    int l;
    int r;
    int h;
};

struct node2
{
    int l;
    int r;
    int minn;
    int maxx;
    int laz;
};

node1 seg[100010];
node2 tree[400010];
int n;

void pushup(int cur)
{
    tree[cur].minn=min(tree[2*cur].minn,tree[2*cur+1].minn);
    tree[cur].maxx=max(tree[2*cur].maxx,tree[2*cur+1].maxx);
}

void pushdown(int cur)
{
    if(tree[cur].laz!=0)
    {
        tree[2*cur].minn=tree[cur].laz;
        tree[2*cur].maxx=tree[cur].laz;
        tree[2*cur].laz=tree[cur].laz;
        tree[2*cur+1].minn=tree[cur].laz;
        tree[2*cur+1].maxx=tree[cur].laz;
        tree[2*cur+1].laz=tree[cur].laz;
        tree[cur].laz=0;
    }
}

void build(int l,int r,int cur)
{
    int m;
    tree[cur].l=l;
    tree[cur].r=r;
    tree[cur].minn=0;
    tree[cur].maxx=0;
    tree[cur].laz=0;
    if(l+1==r) return;
    m=(l+r)/2;
    build(l,m,2*cur);
    build(m,r,2*cur+1);
}

ll solve(int pl,int pr,int h,int cur)
{
    ll res,tmp;
    if(tree[cur].minn>h) return 0;
    if(pl<=tree[cur].l&&tree[cur].r<=pr&&tree[cur].maxx<=h)
    {
        tmp=tree[cur].r-tree[cur].l;
        tree[cur].minn=h;
        tree[cur].maxx=h;
        tree[cur].laz=h;
        return tmp;
    }
    if(tree[cur].l+1==tree[cur].r) return 0;
    pushdown(cur);
    res=0;
    if(pl<tree[2*cur].r) res+=solve(pl,pr,h,2*cur);
    if(pr>tree[2*cur+1].l) res+=solve(pl,pr,h,2*cur+1);
    pushup(cur);
    return res;
}

int main()
{
    ll ans;
    int t,i;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%d",&n);
        build(1,100000,1);
        ans=0;
        for(i=1;i<=n;i++)
        {
            scanf("%d%d%d",&seg[i].l,&seg[i].r,&seg[i].h);
            ans+=solve(seg[i].l,seg[i].r,seg[i].h,1);
            //printf("*%lld*\n",ans);
        }
        printf("%lld\n",ans);
    }
    scanf("%d",&t);
    return 0;
}