#include<bits/stdc++.h>
#define fi first
#define se second
#define pitem item*
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef vector<ll> vl;
const int N=3e5+10;
const int SS=1<<17;
const int INFi=2e9;
const ll INFl=1e13;
const ll mod2=998244353;
const ll mod=1e9+7;
const ll mod3=1000696969;
const ll p=70032301;
const ull p2=913;
const int L=20;
vector<pair<int,int> > t[N];
struct tr{
ll seg[(SS<<1)+10];
void upd(int a,int b,ll x){
for(a+=SS-1,b+=SS+1;(a>>1)!=(b>>1);a>>=1,b>>=1){
if(!(a&1)) seg[a+1]=max(seg[a+1],x);
if(b&1) seg[b-1]=max(seg[b-1],x);
}
}
ll Query(int a){
ll res=0;
for(a+=SS;a>0;a>>=1) res=max(res,seg[a]);
return res;
}
};
tr dp1,dp2;
ll max_weights(int n,int m,vi x,vi y,vi w){
for(int i=1;i<=(SS<<1);i++) dp1.seg[i]=0,dp2.seg[i]=0;
for(int i=0;i<m;i++) t[x[i]+1].push_back({y[i]+1,w[i]});
for(int i=1;i<=n;i++) sort(t[i].begin(),t[i].end());
for(int i=1;i<=n;i++){
int val=dp1.Query(n);
dp1.upd(0,0,dp2.Query(1));
int pop=0;
for(auto [u,c]:t[i]){
if(pop!=u-1) dp1.upd(pop+1,u-1,dp1.Query(pop));
dp1.upd(u,u,dp1.Query(u-1)+(ll)c);
pop=u;
}
if(pop!=n) dp1.upd(pop+1,n,dp1.Query(pop));
pop=n+1;
reverse(t[i].begin(),t[i].end());
if(i==1) continue;
for(auto [u,c]:t[i]){
if(pop!=u+1) dp2.upd(u+1,pop-1,dp2.Query(pop));
dp2.upd(u,u,dp2.Query(u+1)+(ll)c);
pop=u;
}
if(pop!=1) dp2.upd(1,pop-1,dp2.Query(pop));
dp2.upd(1,n+1,val);
}
return dp2.Query(1);
}
int main(){
ios_base::sync_with_stdio(0),cin.tie(0);
int n,m;
cin>>n>>m;
vi x,y,w;
for(int i=1;i<=m;i++){
int a,b,c;
cin>>a>>b>>c;
x.push_back(a),y.push_back(b),w.push_back(c);
}
cout<<max_weights(n,m,x,y,w)<<"\n";
}
Compilation message
/usr/bin/ld: /tmp/ccmNJ1KO.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccfTrqBL.o:fish.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status
