#include<bits/stdc++.h> using namespace std; #define foru(i,a,b) for(int i=(a); i<=(b); ++i) #define ford(i,a,b) for(int i=(a); i>=(b); --i) #define rep(i,a) for(int i=0; i<(a); ++i) #define sz(a) (int)(a).size() #define all(a) (a).begin(),(a).end() #define bit(s,i) (((s)>>(i))&1) #define ii pair<int,int> #define vi vector<int> #define vii vector<ii> #define fi first #define se second #define int long long #define ll long long #define eb emplace_back #define pb push_back #define __builtin_popcount __builtin_popcountll #define _ << " " << template <class X, class Y> bool maxi(X &x, Y y){return x<y?x=y,true:false;} template <class X, class Y> bool mini(X &x, Y y){return x>y?x=y,true:false;} const int N=202020; int n,m; ll res=-1e18; ii cake[N]; struct Node{ Node *lc,*rc; ll sum; int cnt; Node(){ lc=rc=nullptr; sum=0; cnt=0; } }; Node *ver[N]; ll walk(int ql, int qr){ Node *idL=ver[ql-1],*idR=ver[qr]; int l=1, r=1e9; ll res=0; int lt=m; while(l<r){ int mid=(l+r)>>1; int cntR=0; ll sumR=0; if(idR!=0 && idR->rc!=0){ cntR+=idR->rc->cnt; sumR+=idR->rc->sum; } if(idL!=0 && idL->rc!=0){ cntR-=idL->rc->cnt; sumR-=idL->rc->sum; } // cout<<l _ mid _ r _ lt _ cntR _ sumR<<'\n'; if(lt>cntR){ lt-=cntR; res+=sumR; if(idR!=0) idR=idR->lc; if(idL!=0) idL=idL->lc; r=mid; } else{ if(idR!=0) idR=idR->rc; if(idL!=0) idL=idL->rc; l=mid+1; } } // cout<<res _ lt _ l<<'\n'; return res+1LL*lt*l; } ll cost(int i, int j){ if(j-i+1<m) return -1e18; // cerr<<i _ j _ walk(i,j)<<'\n'; return walk(i,j)-2*(cake[j].se-cake[i].se); } void calc(int L, int R, int optL, int optR){ if(L>R) return; int M=(L+R)>>1; ll pos=0, ans=-1e18; foru(opt,optL,min(optR,M)){ if(maxi(ans,cost(opt,M))){ pos=opt; } } maxi(res,ans); calc(L,M-1,optL,pos); calc(M+1,R,pos,optR); } Node *update(int x, Node *old, int l, int r){ if(l==r){ Node *cur=new Node(); *cur=*old; cur->cnt++; cur->sum+=x; return cur; } Node *cur=new Node(); int mid=(l+r)>>1; if(x<=mid){ if(old->lc==0) old->lc=new Node(); cur->lc=update(x,old->lc,l,mid); cur->rc=old->rc; } else{ cur->lc=old->lc; if(old->rc==0) old->rc=new Node(); cur->rc=update(x,old->rc,mid+1,r); } if(cur->lc!=0){ cur->sum+=cur->lc->sum; cur->cnt+=cur->lc->cnt; } if(cur->rc!=0){ cur->sum+=cur->rc->sum; cur->cnt+=cur->rc->cnt; } return cur; } void solve(){ cin>>n>>m; foru(i,1,n) cin>>cake[i].fi>>cake[i].se; sort(cake+1, cake+1+n, [](ii x, ii y){return x.se<y.se;}); // foru(i,1,n) cout<<cake[i].fi<<'\n'; ver[0]=new Node(); foru(i,1,n){ ver[i]=update(cake[i].fi,ver[i-1],1,1e9); } // cout<<walk(1,5)<<'\n'; calc(m,n,1,n); cout<<res<<'\n'; } int32_t main(){ #define task "test" if(fopen(task".inp", "r")){ freopen(task".inp", "r", stdin); freopen(task".out", "w", stdout); } cin.tie(0)->sync_with_stdio(0); int tc=1; //cin>>tc; foru(i,1,tc){ solve(); } }

cake3.cpp: In function 'int32_t main()':
cake3.cpp:150:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  150 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
cake3.cpp:151:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  151 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~