Submission #489705

#	Time	Username	Problem	Language	Result	Execution time	Memory
489705		arwaeystoamneg	A Difficult(y) Choice (BOI21_books)	C++17	100 / 100	3 ms	1096 KiB

books

// EXPLOSION!
#define _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
#include<unordered_set>
#include<unordered_map>
#include<chrono>

using namespace std;
typedef pair<int, int> pii;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pair<int, int>> vpi;
typedef vector<pair<ll, ll>> vpll;

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

#define pb push_back
#define mp make_pair
#define rsz resize
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define f first
#define s second
#define cont continue
//#define endl '\n'
//#define ednl '\n'
#define test int testc;cin>>testc;while(testc--)
#define pr(a, b) trav(x,a)cerr << x << b; cerr << endl;
#define message cout << "Hello World" << endl;
const int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 }; // for every grid problem!!
const ll linf = 4000000000000000000LL;
const ll inf = 1000000007;//998244353    

void pv(vi a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vll a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vector<vi>a) {
	F0R(i, sz(a)) { cout << i << endl; pv(a[i]); cout << endl; }
}void pv(vector<vll>a) { F0R(i, sz(a)) { cout << i << endl; pv(a[i]); }cout << endl; }void pv(vector<string>a) { trav(x, a)cout << x << endl; cout << endl; }
void setIO(string s) {
	ios_base::sync_with_stdio(0); cin.tie(0);
#ifdef arwaeystoamneg
	if (sz(s))
	{
		freopen((s + ".in").c_str(), "r", stdin);
		if (s != "test1")
			freopen((s + ".out").c_str(), "w", stdout);
	}
#endif
}
#ifndef arwaeystoamneg
#include<books.h>
#endif
#ifdef arwaeystoamneg
void result(string x)
{
    cout << x << endl;
    exit(0);
}

namespace
{
    int N, K, S, sUsed;
    long long A;
    vector<long long> seq;
}

void impossible()
{
    result("Impossible (not checked): %d book(s) skimmed");
    exit(0);
}

long long skim(int pos)
{
    printf("skim(%d): ", pos);
    if (pos<1 || pos>N) result("Invalid skim");
    printf("%lld\n", seq[pos]);
    sUsed++;
    if (sUsed > S) result("Out of books to skim");
    return seq[pos];
}

void answer(vector<int> v)
{
    printf("answer({");
    for (int i = 0; i < (int)v.size(); ++i)
    {
        printf("%d", v[i]);
        if (i + 1 != (int)v.size()) printf(", ");
    }
    printf("})\n");

    if ((int)v.size() != K) result("Invalid answer");
    ll sum = 0;
    for (auto x : v) {
        if (x<1 || x>N) result("Invalid answer");
        sum += seq[x];
    }
    if (sum < A || 2 * A < sum) result("Wrong answer");

    result("Correct: %d book(s) skimmed");
    exit(0);
}
#endif
vll a;
void solve(int n, int k, ll A, int s) 
{
    a.rsz(n);
    ll s1 = 0;
    F0R(i, k)a[i] = skim(i + 1);
    s1 = accumulate(all(a), 0LL);
    if (s1 >= A)
    {
        if (s1 > 2 * A)impossible();
        else
        {
            vi ans;
            F0R(i, k)ans.pb(i + 1);
            answer(ans);
        }
    }
    int l = 0, r = n - 1;
    while (l < r)
    {
        int m = (l + r + 1) / 2;
        if (skim(m + 1) < A)
        {
            l = m;
        }
        else
        {
            r = m - 1;
        }
    }
    assert(k <= l);
    F0R(i, k)a[l - i] = skim(l - i + 1);
    ll s2 = 0;
    F0R(i, k)s2 += a[l - i];
    if (s2 <= 2 * A)
    {
        if (s2 >= A)
        {
            vi ans;
            F0R(i, k)ans.pb(l - i + 1);
            answer(ans);
        }
        else
        {
            if (l == n - 1)impossible();
            s1 -= a[k - 1];
            s1 += skim(l + 2);
            if (s1 > 2 * A)impossible();
            vi ans = { l + 2 };
            F0R(i, k - 1)ans.pb(i + 1);
            answer(ans);
        }
    }
    F0R(i, k)
    {
        s1 -= a[i];
        s1 += a[l - i];
        if (s1 >= A)
        {
            vi ans;
            FOR(j, i + 1, k)ans.pb(j + 1);
            F0R(j, i + 1)ans.pb(l - j + 1);
            answer(ans);
        }
    }
    assert(0);
}


#ifdef arwaeystoamneg
int main()
{
    setIO("test1");
    if (scanf("%d %d %lld %d", &N, &K, &A, &S) != 4)
        result("Invalid input");

    seq.resize(N + 1);
    for (int i = 1; i <= N; ++i) {
        if (scanf("%lld", &(seq[i])) != 1) result("Invalid input");
        if (i > 1 && seq[i] <= seq[i - 1]) result("Invalid input");
    }

    solve(N, K, A, S);

    result("No answer");
}
#endif

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 10 / 10
• Subtask 4: 15 / 15
• Subtask 5: 15 / 15
• Subtask 6: 20 / 20
• Subtask 7: 20 / 20