Submission #915550

#	Time	Username	Problem	Language	Result	Execution time	Memory
915550		guagua0407	Cake 3 (JOI19_cake3)	C++17	100 / 100	2128 ms	19792 KiB

cake3

//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int,int>
#define f first
#define s second
#define all(x) x.begin(),x.end()
#define _ ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

int dx[4]={0,0,1,-1};
int dy[4]={1,-1,0,0};

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

const int mxn=2e5+5;
const ll inf=1e18;
ll v[mxn],c[mxn];
ll pre[mxn];
ll sum;
multiset<int> S,T;
int n,m;
int L,R;
ll ans=-inf;

void sir(int l,int r){
    while(L>l){
        L--;
        S.insert(v[L]);
        sum+=v[L];
        if((int)S.size()>m){
            sum-=*S.begin();
            T.insert(*S.begin());
            S.erase(S.begin());
        }
    }
    while(R<r){
        R++;
        S.insert(v[R]);
        sum+=v[R];
        if((int)S.size()>m){
            sum-=*S.begin();
            T.insert(*S.begin());
            S.erase(S.begin());
        }
    }
    while(L<l){
        if(T.find(v[L])!=T.end()){
            T.erase(T.find(v[L]));
        }
        else{
            sum+=*T.rbegin();
            S.insert(*T.rbegin());
            T.erase(prev(T.end()));
            sum-=v[L];
            S.erase(S.find(v[L]));
        }
        L++;
    }
    while(R>r){
        if(T.find(v[R])!=T.end()){
            T.erase(T.find(v[R]));
        }
        else{
            sum+=*T.rbegin();
            S.insert(*T.rbegin());
            T.erase(prev(T.end()));
            sum-=v[R];
            S.erase(S.find(v[R]));
        }
        R--;
    }
}

void go(int l,int r,int tl,int tr){
    if(l>r){
        return;
    }
    int mid=(l+r)/2;
    int best=tl;
    ll cur=-inf;
    for(int i=tl;i<=min(tr,mid-m+1);i++){
        sir(i,mid);
        ll x=sum-2*(c[mid]-c[i]);
        if(x>cur){
            cur=x;
            best=i;
        }
    }
    ans=max(ans,cur);
    go(l,mid-1,tl,best);
    go(mid+1,r,best,tr);
}

int main() {_
    cin>>n>>m;
    vector<pair<int,int>> vec(n);
    for(int i=0;i<n;i++){
        cin>>vec[i].s>>vec[i].f;
    }
    sort(all(vec));
    for(int i=1;i<=n;i++){
        v[i]=vec[i-1].s;
    }
    for(int i=1;i<=n;i++){
        c[i]=vec[i-1].f;
    }
    L=1;
    R=n;
    for(int i=1;i<=n;i++){
        S.insert(v[i]);
        sum+=v[i];
        if((int)S.size()>m){
            sum-=*S.begin();
            T.insert(*S.begin());
            S.erase(S.begin());
        }
    }
    go(m,n,1,n);
    cout<<ans<<'\n';
    return 0;
}
//maybe its multiset not set
//yeeorz
//laborz

Compilation message (stderr)

cake3.cpp: In function 'void setIO(std::string)':
cake3.cpp:15:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cake3.cpp:16:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 19 / 19
• Subtask 3: 76 / 76