Submission #796988

#	Time	Username	Problem	Language	Result	Execution time	Memory
796988		ThMinh_	Cake 3 (JOI19_cake3)	C++14	100 / 100	825 ms	206280 KiB

cake3

#include<bits/stdc++.h>
#define forin(i, a, b) for(int i = a; i <= b; ++i)
#define ll long long
using namespace std;
const int N = 2e5 + 10;
int n, m;
ll ans, inf = 2e18;
ll s[N];
struct it {
    int cnt;
    ll sum;
    it* lf;
    it* rt;
    it() : cnt(), sum(), lf(), rt() { }
    void build(int f = 1, int l = n) {
        if(f == l) return;
        int mid = f + l >> 1;
        lf = new it();
        rt = new it();
        lf -> build(f, mid);
        rt -> build(mid + 1, l);
    }
    void up(int i, ll val, int f = 1, int l = n) {
        if(f == l) {
            cnt = 1;
            sum = val;
            return;
        }
        int mid = f + l >> 1;
        if(i <= mid) {
            lf = new it(*lf);
            lf -> up(i, val, f, mid);
        }
        else {
            rt = new it(*rt);
            rt -> up(i, val, mid + 1, l);
        }
        sum = cnt = 0;
        if(lf) sum += lf -> sum, cnt += lf -> cnt;
        if(rt) sum += rt -> sum, cnt += rt -> cnt;
    }
};
ll sum(it* id) {
    return id -> sum;
}
int cnt(it* id) {
    return id -> cnt;
}
ll get(it* id1, it* id2, int f = 1, int l = n, int k = m - 2) {
    if(f == l) return sum(id2) - sum(id1);
    int mid = f + l >> 1;
    int res = cnt(id2 -> rt) - cnt(id1 -> rt);
    ll val = sum(id2 -> rt) - sum(id1 -> rt);
    if(res < k) return val + get(id1 -> lf, id2 -> lf, f, mid, k - res);
    return get(id1 -> rt, id2 -> rt, mid + 1, l, k);
}
struct piece {
    ll v, c;
    int pos;
};
piece p[N];
vector<it*> tr;
void solve(int from = 1, int to = n, int f = 1, int l = n) {
    if(f > l) return;
    int mid = f + l >> 1, nxt = 0;
    ll &a = s[mid];
    forin(i, from, min(to, mid)) {
        ll val = -1e18;
        if(mid - i + 1 >= m) {
            val = get(tr[i], tr[mid - 1]) + p[mid].v + p[i].v - 2 * (p[mid].c - p[i].c);
        }
        if(a < val) {
            a = val;
            nxt = i;
        }
    }
    solve(from, nxt, f, mid - 1);
    solve(nxt, to, mid + 1, l);
}
int main () {
    cin.tie(0)->sync_with_stdio(0);
    if(fopen("Task.inp","r")) {
        freopen("Task.inp","r",stdin);
        freopen("WA.out","w",stdout);
    }
    cin>>n>>m;
    forin(i, 1, n) cin>>p[i].v>>p[i].c;
    sort(p + 1, p + n + 1, [] (piece a, piece b) {
        return a.v < b.v;
    });
    forin(i, 1, n) p[i].pos = i;
    sort(p + 1, p + n + 1, [] (piece a, piece b) {
        return a.c < b.c;
    });
    tr.resize(n + 1);
    tr[0] = new it();
    tr[0] -> build();
    forin(i, 1, n) {
        tr[i] = new it(*tr[i - 1]);
        tr[i] -> up(p[i].pos, p[i].v);
        s[i] = -inf;
    }
    solve();
    ans = -inf;
    forin(i, 1, n) ans = max(ans, s[i]);
    cout<<ans;
}

Compilation message (stderr)

cake3.cpp: In member function 'void it::build(int, int)':
cake3.cpp:17:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   17 |         int mid = f + l >> 1;
      |                   ~~^~~
cake3.cpp: In member function 'void it::up(int, long long int, int, int)':
cake3.cpp:29:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   29 |         int mid = f + l >> 1;
      |                   ~~^~~
cake3.cpp: In function 'long long int get(it*, it*, int, int, int)':
cake3.cpp:51:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   51 |     int mid = f + l >> 1;
      |               ~~^~~
cake3.cpp: In function 'void solve(int, int, int, int)':
cake3.cpp:65:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   65 |     int mid = f + l >> 1, nxt = 0;
      |               ~~^~~
cake3.cpp: In function 'int main()':
cake3.cpp:83:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |         freopen("Task.inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
cake3.cpp:84:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   84 |         freopen("WA.out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~

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