Submission #120770

#	Time	Username	Problem	Language	Result	Execution time	Memory
120770		songc	Cake 3 (JOI19_cake3)	C++14	100 / 100	1236 ms	183812 KiB

cake3

#include <bits/stdc++.h>
#define INF (1ll << 60)
using namespace std;
typedef long long LL;
typedef pair<LL, LL> pii;

int N, M;
pii A[202020];
vector<int> comp;
LL ans = -INF;

struct Node{
    int cnt;
    LL sum;
    Node *lc, *rc;
    Node();
} *PST[202020], *NIL;

Node :: Node(){
    lc = rc = NIL;
    cnt = sum = 0;
}

void update(Node *pr, Node *nw, int s, int e, int t){
    nw->cnt = pr->cnt+1;
    nw->sum = pr->sum+comp[t];
    if (s == e) return;
    int mid = (s+e)/2;
    if (t <= mid){
        nw->lc = new Node;
        nw->rc = pr->rc;
        update(pr->lc, nw->lc, s, mid, t);
    }
    else{
        nw->lc = pr->lc;
        nw->rc = new Node;
        update(pr->rc, nw->rc, mid+1, e, t);
    }
}

LL query(Node *st, Node *ed, int s, int e, int k){
    if (k <= 0) return 0;
    if (s == e) return k * comp[s];
    int mid = (s+e)/2;
    if (ed->rc->cnt - st->rc->cnt > k) return query(st->rc, ed->rc, mid+1, e, k);
    return ed->rc->sum - st->rc->sum + query(st->lc, ed->lc, s, mid, k - ed->rc->cnt + st->rc->cnt);
}

void DNC(int s, int e, int st, int ed){
    if (s > e) return;
    int mid = (s+e)/2;
    LL Max=-INF, id=0;
    for (int i=st; i<=min(ed, mid-M+1); i++){
        LL ret = query(PST[i], PST[mid-1], 0, comp.size(), M-2);
        ret += A[i].second + A[mid].second - 2*(A[mid].first - A[i].first);
        if (Max < ret) Max = ret, id = i;
    }
    ans = max(ans, Max);
    DNC(s, mid-1, st, id);
    DNC(mid+1, e, id, ed);
}

int main(){
    NIL = new Node;
    NIL->lc = NIL->rc = NIL;

    scanf("%d %d", &N, &M);
    for (int i=1; i<=N; i++){
        scanf("%lld %lld", &A[i].second, &A[i].first);
        comp.push_back(A[i].second);
    }
    sort(A+1, A+N+1);
    sort(comp.begin(), comp.end());
    comp.erase(unique(comp.begin(), comp.end()), comp.end());

    PST[0] = new Node;
    for (int i=1; i<=N; i++){
        PST[i] = new Node;
        update(PST[i-1], PST[i], 0, comp.size(), lower_bound(comp.begin(), comp.end(), A[i].second)-comp.begin());
    }
    DNC(M, N, 1, N);
    printf("%lld\n", ans);
    return 0;
}

Compilation message (stderr)

cake3.cpp: In function 'int main()':
cake3.cpp:67:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &N, &M);
     ~~~~~^~~~~~~~~~~~~~~~~
cake3.cpp:69:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld %lld", &A[i].second, &A[i].first);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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