悬关

#include<bits/stdc++.h>
#define int long long
using namespace std;
int n,h,l,r,ans,d[80004];
struct pingban{
	int h,l,r;
}a[80004];
bool cmp(pingban a,pingban b){
	return a.h<b.h;
}
signed main(){
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>a[i].h>>a[i].l>>a[i].r;
		a[i].l++;a[i].r--;
	}
	sort(a+1,a+n+1,cmp);
	for(int i=1;i<=n;i++){
		ans+=abs(d[a[i].l]-a[i].h);
		ans+=abs(d[a[i].r]-a[i].h);
		for(int j=a[i].l;j<=a[i].r;j++)d[j]=a[i].h;
	}
	
	cout<<ans;
}