Submission #397191

#	Time	Username	Problem	Language	Result	Execution time	Memory
397191		rocks03	Packing Biscuits (IOI20_biscuits)	C++14	100 / 100	38 ms	1292 KiB

biscuits

//#pragma GCC target("avx2")
//#pragma GCC optimization("O3")
//#pragma GCC optimization("unroll-loops")
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define ff first
#define ss second
#define pb push_back
#define SZ(x) ((int)(x).size())
#define all(x) x.begin(), x.end()
#define rep(i, a, b) for(int i = (a); i < (b); i++)
#define per(i, a, b) for(int i = (a); i >= (b); i--)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int N = 60;
ll x;
vector<ll> a;

unordered_map<ll, ll> memo;
ll f(ll n){
    if(n == 0) return 1;
    if(memo[n]) return memo[n];
    ll& ans = memo[n];
    int hbit = 63 - __builtin_clzll(n);
    ll max_y = min(a[hbit] / x, n);
    if(max_y >= (1ll << hbit)){
        ans += f(max_y - (1ll << hbit));
    }
    ans += f((1ll << hbit) - 1);
    return ans;
}

long long count_tastiness(long long X, vector<long long> A){
    while(SZ(A) < N) A.pb(0);
    rep(i, 0, N) A[i] = A[i] * (1ll << i);
    rep(i, 1, N) A[i] += A[i - 1];
    x = X; a = A;
    memo.clear();
    return f(a.back());
}

• Subtask 1: 9 / 9
• Subtask 2: 12 / 12
• Subtask 3: 21 / 21
• Subtask 4: 35 / 35
• Subtask 5: 23 / 23