Submission #1309794

#	Time	Username	Problem	Language	Result	Execution time	Memory
1309794		edo	Autobahn (COI21_autobahn)	C++20	100 / 100	85 ms	17432 KiB

autobahn

#include <bits/stdc++.h>

using namespace std;
using ll   = long long;
using vi   = vector<int>;
using vll  = vector<ll>;
using vvi  = vector<vi>;
using vvll = vector<vll>;
using pii  = pair<int,int>;
using pll  = pair<ll,ll>;
using ui    = unsigned int;
using ull   = unsigned long long;
using pui   = pair<ui,ui>;
using pull  = pair<ull,ull>;
using i128 = __int128_t;

template<typename T>
using vc = std::vector<T>;


#define YES cout << "YES\n"
#define NO  cout << "NO\n"
#define yes cout << "yes\n"
#define no  cout << "no\n"
#define Yes cout << "Yes\n"
#define No  cout << "No\n"

template<typename T> void sc(T &x) { cin >> x; }
template<typename T, typename U> void sc(pair<T,U> &p) { sc(p.first), sc(p.second); }
template<typename T> void sc(vector<T> &v) { for (auto &x : v) sc(x); }
template<typename... A> void sc(A&... a) { (sc(a), ...); }


template<typename T> void _pt(const T &x){cout << x;}
template<typename T, typename U> void _pt(const pair<T,U> &p){_pt(p.first); cout << ' '; _pt(p.second);}
template<typename T> void _pt(const vector<T> &v){bool f=1; for(auto &x:v){if(!f) cout<<' '; _pt(x); f=0;}}
template<typename... A> void pt(const A&... a){(_pt(a), ...);}


template<typename T, typename U> bool umin(T &a, const U &b) { return b < a ? (a = b, true) : false; }
template<typename T, typename U> bool umax(T &a, const U &b) { return b > a ? (a = b, true) : false; }
template<typename T> T maxel(const vector<T>& v){ return *max_element(v.begin(), v.end()); }
template<typename T> T minel(const vector<T>& v){ return *min_element(v.begin(), v.end()); }
template<typename T, int N> T maxel(T (&a)[N]) { return *max_element(a, a + N); }
template<typename T, int N> T minel(T (&a)[N]) { return *min_element(a, a + N); }


template<typename C, typename T> auto lb(C& c, const T& x){ return std::lower_bound(c.begin(), c.end(), x); }
template<typename C, typename T> auto ub(C& c, const T& x){ return std::upper_bound(c.begin(), c.end(), x); }

template<typename T> auto lb(std::set<T>& s, const T& x){ return s.lower_bound(x); }
template<typename T> auto ub(std::set<T>& s, const T& x){ return s.upper_bound(x); }
template<typename T> auto lb(const std::set<T>& s, const T& x){ return s.lower_bound(x); }
template<typename T> auto ub(const std::set<T>& s, const T& x){ return s.upper_bound(x); }

#define GET_MACRO(_1,_2,_3,_4,NAME,...) NAME
#define FOR1(n)            for (int i=0; i<(n); ++i)
#define FOR2(i,n)          for (int i=0; i<(n); ++i)
#define FOR3(i,l,r)        for (int i=(l); i<(r); ++i)
#define FOR4(i,l,r,k)      for (int i=(l); i<(r); i+=(k))
#define FOR(...)           GET_MACRO(__VA_ARGS__, FOR4, FOR3, FOR2, FOR1)(__VA_ARGS__)
#define ROF1(n)            for (int i=(n)-1; i>=0; --i)
#define ROF2(i,n)          for (int i=(n)-1; i>=0; --i)
#define ROF3(i,l,r)        for (int i=(r)-1; i>=(l); --i)
#define ROF4(i,l,r,k)      for (int i=(r)-1; i>=(l); i-=(k))
#define ROF(...)           GET_MACRO(__VA_ARGS__, ROF4, ROF3, ROF2, ROF1)(__VA_ARGS__)
#define all(c)   (c).begin(), (c).end()
#define allr(c)  (c).rbegin(), (c).rend()
#define eb       emplace_back
#define mp       make_pair
#define mt       make_tuple
#define fi       first
#define se       second
#define pb       push_back
#define trav(x,a) for (auto &x : (a))
#define sz(a) ((int)(a).size())
#define mem(a,v) memset(a, v, sizeof(a))
#define nl pt("\n")


int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, k, x;
    sc(n, k, x);
    
    vc<pii> occE;
    vc<pii> extW;
    vi xs;
    FOR(n) {
        int l, t, r;
        sc(l, t, r);
        r++;
        xs.pb(l); xs.pb(r);
        occE.eb(l, 1); occE.eb(r, -1);
        if(l + t < r) {
            xs.pb(l + t);
            extW.eb(l + t, 1); extW.eb(r, -1);
        }
    }
    
    sort(all(occE)); sort(all(extW)); sort(all(xs));
    xs.erase(unique(all(xs)), xs.end());

    int M = sz(xs);
    vll A(M), W(M);

    {
        int p = 0, i = 0;
        while(i < sz(occE)) {
            ll sum = 0;
            int tm = occE[i].fi;
            while(i < sz(occE) && occE[i].fi == tm) {
                sum += occE[i].se;
                i++;
            }
            while(p < M && xs[p] < tm) p++;
            if(p < M && xs[p] == tm) A[p] += sum;
        }
    }
    {
        int p = 0, i = 0;
        while(i < sz(extW)) {
            ll sum = 0;
            int tm = extW[i].fi;
            while(i < sz(extW) && extW[i].fi == tm) {
                sum += extW[i].se;
                i++;
            }
            while(p < M && xs[p] < tm) p++;
            if(p < M && xs[p] == tm) W[p] += sum;
        }
    }


    vll segLen, segW;
    ll occ = 0, ext = 0;
    FOR(M - 1) {
        occ += A[i];
        ext += W[i];
        ll len = xs[i + 1] - xs[i];
        ll w = occ >= k ? ext : 0;
        segLen.pb(len);
        segW.pb(w);
    }


    ll off = 0;
    int L = 0;
    ll totLen = 0;
    ll tot = 0;
    ll ans = 0;
    FOR(R, sz(segLen)) {
        totLen += segLen[R];
        tot += segLen[R] * segW[R];
        while(totLen > x) {
            ll need = totLen - x;
            ll can = segLen[L] - off;
            ll take = min(can, need);
            totLen -= take;
            tot -= take * segW[L];
            off += take;

            if(segLen[L] == off) {
                off = 0;
                L++;
            }
        }

        umax(ans, tot);
    }

    pt(ans); nl;
    return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 50 / 50