Submission #1055564

#	Time	Username	Problem	Language	Result	Execution time	Memory
1055564		Trent	Packing Biscuits (IOI20_biscuits)	C++17	9 / 100	1052 ms	816228 KiB

biscuits

#include "biscuits.h"
#include "bits/stdc++.h"
using namespace std;
#define forR(i, x) for(int i = 0; i < (x); ++i)
#define REP(i, a, b) for(int i = (a); i < (b); ++i)
#define all(x) x.begin(), x.end()
typedef long long ll;
typedef vector<ll> vll;

ll INF = 1e18 + 10;
ll mult(ll a, ll b) {
    return a > INF / b ? INF : a * b;
}
ll valOf(ll msk, vll& dc) {
    ll ret = 0;
    forR(i, dc.size()) if(msk & (1LL << i)) ret = min(INF, ret + dc[dc.size() - 1 - i]);
    return ret;
}
long long count_tastiness(long long x, std::vector<long long> a) {
    a.insert(a.begin(), (ll) 0);
    int k = 60;
    while(a.size() < k) a.push_back(0);
    vll ftp(k);
    vll sm(k);
    sm[0] = a[0];
    REP(i, 1, k) sm[i] = sm[i-1] + (1LL << (i-1)) * a[i];

    forR(i, k) {
        if(i == 0) ftp[i] = 1;
        else {
            cerr << i << ": \n";
            ll st = sm[i];
            vll dc = {mult(1LL << (i-1), x)};
            ll msk = 0;
            for(int j = i-1; j >= 0; --j) {
                // st - dc(lo) >= sm[j], st - dc(hi) < sm[j]
                if(st - valOf(msk, dc) >= sm[j]) {
                    ll lo=msk, hi=(1LL << dc.size());
                    while(hi - lo > 1) {
                        int mid = (lo+hi)/2;
                        if(st - valOf(mid, dc) >= sm[j]) lo = mid;
                        else hi = mid;
                    }
                    ftp[i] += (hi - msk) * ftp[j];
                    cerr << j << ' ' << hi << ' ' << ftp[i] << ' ' << dc.size() << '\n';
                    if(hi == (1LL << dc.size())) break;
                    msk = hi << 1;
                    dc.push_back((1LL << (j-1)) * x);
                } else {
                    msk <<= 1;
                    dc.push_back((1LL << (j-1)) * x);
                }
            }
        }
    }

    vll vals = {sm[k-1]};
    for(int i = k - 1; i > 0; --i) {
        vll nex;
        for(ll j : vals) {
            j = min(j, sm[i]);
            nex.push_back(j);
            if(j - mult(1LL << (i-1), x) >= 0) nex.push_back(j - (1LL << (i-1)) * x);
        }
        vals.swap(nex);
    }

    forR(i, k) cerr << sm[i] << ' ';
    cerr << '\n';
    forR(i, k) cerr << ftp[i] << ' ';
    cerr << '\n';
    assert(ftp[k-1] == vals.size());
    return vals.size();
}

Compilation message (stderr)

biscuits.cpp: In function 'll valOf(ll, vll&)':
biscuits.cpp:4:37: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    4 | #define forR(i, x) for(int i = 0; i < (x); ++i)
      |                                     ^
biscuits.cpp:16:5: note: in expansion of macro 'forR'
   16 |     forR(i, dc.size()) if(msk & (1LL << i)) ret = min(INF, ret + dc[dc.size() - 1 - i]);
      |     ^~~~
biscuits.cpp: In function 'long long int count_tastiness(long long int, std::vector<long long int>)':
biscuits.cpp:22:20: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   22 |     while(a.size() < k) a.push_back(0);
      |           ~~~~~~~~~^~~
In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from biscuits.cpp:2:
biscuits.cpp:72:21: warning: comparison of integer expressions of different signedness: '__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   72 |     assert(ftp[k-1] == vals.size());

• Subtask 1: 9 / 9
• Subtask 2: 0 / 12
• Subtask 3: 0 / 21
• Subtask 4: 0 / 35
• Subtask 5: 0 / 23