Submission #129047

#	Time	Username	Problem	Language	Result	Execution time	Memory
129047		Plurm	Cake 3 (JOI19_cake3)	C++11	24 / 100	481 ms	183540 KiB

cake3

#include <bits/stdc++.h>
using namespace std;
int n,m;
vector<pair<int,int> > pieces;
const int COEFF = 16;
const int MXN = 200005;
int segT[COEFF*MXN];
long long qs[MXN];
long long qsegT[COEFF*MXN];
int lb[COEFF*MXN];
int rb[COEFF*MXN];
int llink[COEFF*MXN];
int rlink[COEFF*MXN];
int nodesz;
inline int newnode(int o = -1){
    int c = ++nodesz;
    if(o != -1){
        qsegT[c] = qsegT[o];
        segT[c] = segT[o];
        lb[c] = lb[o];
        rb[c] = rb[o];
        llink[c] = llink[o];
        rlink[c] = rlink[o];
    }
    return c;
}
int build(int l, int r){
    int c = newnode();
    lb[c] = l;
    rb[c] = r;
    if(l == r) return c;
    int k = (l + r)/2;
    llink[c] = build(l, k);
    rlink[c] = build(k+1, r);
    return c;
}
int update(int o, int idx, int amt){
    int c = newnode(o);
    if(lb[c] == rb[c]){
        segT[c] = 1;
        qsegT[c] = amt;
        return c;
    }
    int k = (lb[c] + rb[c])/2;
    if(idx <= k){
        llink[c] = update(llink[o], idx, amt);
    }else{
        rlink[c] = update(rlink[o], idx, amt);
    }
    segT[c] = segT[llink[c]] + segT[rlink[c]];
    qsegT[c] = qsegT[llink[c]] + qsegT[rlink[c]];
    return c;
}
long long sumdescent(int c, int o, int ord){
    if(ord == 0) return 0ll;
    if(ord == segT[c] - segT[o]) return qsegT[c] - qsegT[o];
    if(lb[c] == rb[c]) return qsegT[c] - qsegT[o];
    int lcnt = segT[llink[c]] - segT[llink[o]];
    if(lcnt >= ord) return sumdescent(llink[c], llink[o], ord);
    else return sumdescent(rlink[c], rlink[o], ord - lcnt) + qsegT[llink[c]] - qsegT[llink[o]];
}
vector<int> rootlist;
long long query(int l, int r){
    int croot = rootlist[r];
    int items = r-l+1 - (m-2);
    long long qr = sumdescent(rootlist[r], rootlist[l-1], items);
    long long rsq = qs[r] - qs[l-1];
    return rsq - qr;
}
long long solve(int l, int r, int lb, int rb){
    int mid = (l + r)/2;
    long long ans = -1e18;
    int mindex = -1;
    for(int i = lb; i <= min(mid-m+1,rb); i++){
        long long cur = query(i+1, mid-1) + 1ll * pieces[i].first + 1ll * pieces[mid].first + 2ll * pieces[i].second - 2ll * pieces[mid].second;
        if(cur > ans){
            ans = cur;
            mindex = i;
        }
    }
    if(l <= mid-1) ans = max(ans, solve(l, mid-1, lb, mindex == -1 ? rb : mindex));
    if(mid+1 <= r) ans = max(ans, solve(mid+1, r, mindex == -1 ? lb : mindex, rb));
    return ans;
}
int mp[MXN];
int main(){
    scanf("%d%d",&n,&m);
    int v,c;
    vector<pair<int,int> > rankofv;
    for(int i = 0; i < n; i++){
        scanf("%d%d",&v,&c);
        pieces.emplace_back(v,c);
    }
    stable_sort(pieces.begin(), pieces.end(), [](pair<int,int> x, pair<int,int> y){
        return x.second < y.second;
    });
    for(int i = 0; i < n; i++){
        rankofv.emplace_back(pieces[i].first,i);
    }
    sort(rankofv.begin(), rankofv.end());
    for(int i = 0; i < rankofv.size(); i++){
        mp[rankofv[i].second] = i;
    }
    qs[0] = pieces[0].first;
    for(int i = 1; i < n; i++){
        qs[i] = qs[i-1] + 1ll * pieces[i].first;
    }
    int initroot = build(0,n-1);
    int lastroot = initroot;
    for(int i = 0; i < n; i++){
        int idx = mp[i];
        //printf("DBG %d %d %lld\n",idx,pieces[i].first,qsegT[lastroot]);
        rootlist.push_back(update(lastroot, idx, pieces[i].first));
        lastroot = rootlist.back();
    }
    long long ans = solve(m-1,n-1,0,n-1);
    printf("%lld\n",ans);
    return 0;
}

Compilation message (stderr)

cake3.cpp: In function 'long long int query(int, int)':
cake3.cpp:64:9: warning: unused variable 'croot' [-Wunused-variable]
     int croot = rootlist[r];
         ^~~~~
cake3.cpp: In function 'int main()':
cake3.cpp:101:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < rankofv.size(); i++){
                    ~~^~~~~~~~~~~~~~~~
cake3.cpp:87:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
     ~~~~~^~~~~~~~~~~~~~
cake3.cpp:91:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d",&v,&c);
         ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 19 / 19
• Subtask 3: 0 / 76