Submission #470821

#	Time	Username	Problem	Language	Result	Execution time	Memory
470821		MarcoMeijer	Fireworks (APIO16_fireworks)	C++14	100 / 100	407 ms	105836 KiB

fireworks

#include <bits/stdc++.h>
using namespace std;
 
// macros
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define FOR(a,b) for(auto& a : b)
#define all(a) a.begin(), a.end()
#define INF 1e18
#define EPS 1e-9
#define pb push_back
#define popb pop_back
#define fi first
#define se second
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
 
// input
template<class T> void IN(T& x) {cin >> x;}
template<class H, class... T> void IN(H& h, T&... t) {IN(h); IN(t...); }
 
// output
template<class T1, class T2> void OUT(const pair<T1,T2>& x);
template<class T> void OUT(const vector<T>& x);
template<class T> void OUT(const T& x) {cout << x;}
template<class H, class... T> void OUT(const H& h, const T&... t) {OUT(h); OUT(t...); }
template<class T1, class T2> void OUT(const pair<T1,T2>& x) {OUT(x.fi,' ',x.se);}
template<class T> void OUT(const vector<T>& x) {RE(i,x.size()) OUT(i==0?"":" ",x[i]);}
template<class... T> void OUTL(const T&... t) {OUT(t..., "\n"); }
template<class H> void OUTLS(const H& h) {OUTL(h); }
template<class H, class... T> void OUTLS(const H& h, const T&... t) {OUT(h,' '); OUTLS(t...); }
 
// dp
template<class T> bool ckmin(T&a, T&b) { bool bl = a > b; a = min(a,b); return bl;}
template<class T> bool ckmax(T&a, T&b) { bool bl = a < b; a = max(a,b); return bl;}
 
void program();
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    program();
}
 
 
//===================//
//   begin program   //
//===================//
 
const int MX = 3e5+10;
const int N = (1<<20);

ll n, m;
ll p[MX], c[MX];
vi chl[MX];

struct Func {
    ll y = 0, delta = 0;
    multiset<ll> ms;
};

void combine(Func& res, Func& b) {
    if(res.ms.size() < b.ms.size())
        swap(res,b);
    res.y += b.y;
    res.delta += b.delta;
    FOR(x,b.ms)
        res.ms.insert(x);
}
ll computeMin(Func& f) {
    ll v = f.y;
    ll delta = f.delta;
    ll lx = 0;
    FOR(i,f.ms) {
        ll cx = i;
        if(cx >= 0) {
            v += delta*(cx-lx);
            lx = cx;
        }
        delta++;
        if(delta == 0)
            return v;
    }
    return v;
}
ll computePos(Func& f, ll x) {
    ll v = f.y;
    ll delta = f.delta;
    ll lx = 0;
    FOR(i,f.ms) {
        ll cx = i;
        if(cx >= x) {
            v += delta*(x-lx);
            return v;
        }
        if(cx >= 0) {
            v += delta*(cx-lx);
            lx = cx;
        }
        delta++;
    }
    v += delta*(x-lx);
    return v;
}

Func f[MX];

void program() {
    IN(n,m);
    p[1] = 0, c[1] = 0;
    REP(u,2,n+m+1) IN(p[u],c[u]);
    n += m;
    RE1(u,n) chl[p[u]].pb(u);


    REV(u,1,n+1) {
        if(chl[u].empty()) {
            // base case
            f[u].y = c[u];
            f[u].delta = -1;
            f[u].ms.insert(c[u]);
            f[u].ms.insert(c[u]);
        } else {
            FOR(v,chl[u])
                combine(f[u], f[v]);

            // remove slopes bigger then 1
            while(f[u].delta + f[u].ms.size() > 1) {
                f[u].ms.erase(--f[u].ms.end());
            }

            // remember positions op last two elements
            ll x2 = *(--f[u].ms.end()) + c[u]; f[u].ms.erase(--f[u].ms.end()); // delta 1
            ll x1 = *(--f[u].ms.end()) + c[u]; f[u].ms.erase(--f[u].ms.end()); // delta 0

            // shift graph to left
            f[u].y += c[u];

            // reinsert last two elements
            f[u].ms.insert(x1);
            f[u].ms.insert(x2);
        }

    }

    OUTL(computeMin(f[1]));
}

• Subtask 1: 7 / 7
• Subtask 2: 19 / 19
• Subtask 3: 29 / 29
• Subtask 4: 45 / 45