Submission #421574

#	Time	Username	Problem	Language	Result	Execution time	Memory
421574		usachevd0	Packing Biscuits (IOI20_biscuits)	C++17	0 / 100	1085 ms	416 KiB

biscuits

#include <bits/stdc++.h>
#ifndef LOCAL
    #include "biscuits.h"
#endif

using namespace std;

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define Time (clock() * 1.0 / CLOCKS_PER_SEC)
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
using ld = long double;
template<typename T1, typename T2> bool chkmin(T1& x, T2 y) {
    return y < x ? (x = y, true) : false;
}
template<typename T1, typename T2> bool chkmax(T1& x, T2 y) {
    return y > x ? (x = y, true) : false;
}
void debug_out() {
    cerr << endl;
}
template<typename T1, typename... T2> void debug_out(T1 A, T2... B) {
    cerr << ' ' << A;
    debug_out(B...);
}
template<typename T> void mdebug_out(T* a, int n) {
    for (int i = 0; i < n; ++i)
        cerr << a[i] << ' ';
    cerr << endl;
}
#ifdef LOCAL
    #define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
    #define mdebug(a, n) cerr << #a << ": ", mdebug_out(a, n)
#else
    #define debug(...) 1337
    #define mdebug(a, n) 1337
#endif
template<typename T> ostream& operator << (ostream& stream, const vector<T>& v) {
    for (auto& e : v)
        stream << e << ' ';
    return stream;
}
template<typename T1, typename T2> ostream& operator << (ostream& stream, const pair<T1, T2>& p) {
    return stream << p.first << ' ' << p.second;
}


const ll INF64 = 1e18;

ll count_tastiness_stu(ll x, vector<ll> a) {
    int k = a.size();
    
    ll sum = 0;
    for (int i = 0; i < k; ++i)
        sum += (a[i] << i);
    
    auto good = [&](ll y) -> bool {
        vector<ll> b(all(a));
        int j = k - 1;
        for (int i = k - 1; i >= 0; --i) {
            chkmin(j, i);
            if ((y >> i) & 1) {
                ll need = x;
                for (; j >= 0; --j) {
                    if (b[j] >= need) {
                        b[j] -= need;
                        need = 0;
                        break;
                    }
                    need -= b[j];
                    b[j] = 0;
                    need *= 2;
                }
                if (need) return false;
            }
        }
        return true;
    };
    
    ll ans = 1;
    for (ll y = 1; y <= 200000 && x * y <= sum; ++y) {
        ans += good(y);
    }
    return ans;
}

ll count_tastiness(ll x, vector<ll> a) {
    int k = a.size();
    
    ll sum = 0;
    for (int i = 0; i < k; ++i)
        sum += (a[i] << i);
    
    auto good = [&](ll y) -> bool {
        vector<ll> b(all(a));
        int j = k - 1;
        for (int i = k - 1; i >= 0; --i) {
            chkmin(j, i);
            if ((y >> i) & 1) {
                ll need = x;
                for (; j >= 0; --j) {
                    if (b[j] >= need) {
                        b[j] -= need;
                        need = 0;
                        break;
                    }
                    need -= b[j];
                    b[j] = 0;
                    need *= 2;
                }
                if (need) return false;
            }
        }
        return true;
    };
    
    ll ans = 0;
    int tot = 0;
    
    vector<ll> b(all(a));
    function<void(int)> brute = [&](int i) {
        assert(++tot <= 13e6);
        if (i == -1) {
            // debug(b);
            ++ans;
            return;
        }
        ll ans0 = ans;
        brute(i - 1);
        ll dans = ans - ans0;
        ll need = x;
        vector<ll> new_b(all(b));
        int j = i;
        for (j = i; j >= 0; --j) {
            if (j >= new_b.size()) {
                need *= 2;
                if (need > INF64) break;
                continue;
            }
            if (new_b[j] >= need) {
                new_b[j] -= need;
                need = 0;
                break;
            }
            need -= new_b[j];
            new_b[j] = 0;
            need *= 2;
        }
        if (!need) {
            if (j < i) {
                swap(b, new_b);
                brute(i - 1);
                swap(b, new_b);
            } else ans += dans;
        }
    };
    brute(59);
    return ans;
    
    // ll ans = 1;
    // for (ll y = 1; y <= 200000 && x * y <= sum; ++y) {
    //     ans += good(y);
    // }
    // return ans;
}


#ifdef LOCAL

mt19937 rng(228);
ll randll(ll L, ll R) {
    return rng() % (R - L + 1) + L;
}

int32_t main() {
    #ifdef LOCAL
        freopen("in", "r", stdin);
    #endif
    ios::sync_with_stdio(0);
    cin.tie(0);
    
    /*const ll C = 4;
    for (int test = 1; ; ++test) {
        ll x = 1;
        int k = 2;
        vector<ll> a(k);
        for (auto& x : a)
            x = randll(0, C);
        if (count_tastiness(x, a) != count_tastiness_stu(x, a)) {
            cout << "1\n";
            cout << x << ' ' << k << '\n';
            cout << a << '\n';
            exit(0);
        }
        if (test % 1000 == 0) debug(test);
    }/**/
    
    int q;
    assert(scanf("%d", &q) == 1);
    vector<int> k(q);
    vector<long long> x(q);
    vector<vector<long long>> a(q);
    vector<long long> results(q);
    for (int t = 0; t < q; t++) {
        assert(scanf("%d%lld", &k[t], &x[t]) == 2);
        a[t] = vector<long long>(k[t]);
        for (int i = 0; i < k[t]; i++) {
            assert(scanf("%lld", &a[t][i]) == 1);
        }
    }
    fclose(stdin);

    for (int t = 0; t < q; t++) {
        results[t] = count_tastiness(x[t], a[t]);
    }
    for (int t = 0; t < q; t++) {
        printf("%lld\n", results[t]);
    }
    fclose(stdout);
    
    
    return 0;
}


#endif

Compilation message (stderr)

biscuits.cpp:204:6: warning: "/*" within comment [-Wcomment]
  204 |     }/**/
      |       
biscuits.cpp: In lambda function:
biscuits.cpp:143:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  143 |             if (j >= new_b.size()) {
      |                 ~~^~~~~~~~~~~~~~~
biscuits.cpp: In function 'll count_tastiness(ll, std::vector<long long int>)':
biscuits.cpp:102:10: warning: variable 'good' set but not used [-Wunused-but-set-variable]
  102 |     auto good = [&](ll y) -> bool {
      |          ^~~~

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