Submission #1188476

#	Time	Username	Problem	Language	Result	Execution time	Memory
1188476		DanielPr8	A Difficult(y) Choice (BOI21_books)	C++20	60 / 100	1 ms	1948 KiB

books

#include <bits/stdc++.h>
#include"books.h"
using namespace std;
using ll = __int128_t;
using vll = vector<ll>;
using vvl = vector<vll>;
using pll = pair<ll,ll>;
using vpl = vector<pll>;
using vvp = vector<vpl>;
#define f first
#define s second
#define pb push_back
#define all(v) v.begin(),v.end()

/*
void __attribute__((noreturn)) __attribute__((format(printf, 1, 2))) result(const char *msg, ...)
{
    va_list args;
    va_start(args, msg);
    vfprintf(stderr, msg, args);
    fprintf(stderr, "\n");
    va_end(args);
    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", sUsed);
    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");
   	long long 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", sUsed);
    exit(0);
}
*/



vll pas;
ll ski(ll a){
    if(pas[a]==-1)return pas[a]=skim(a);
    return pas[a];
}

void solve(int n, int k, long long a, int Q) {
    ll s = 1, e = n, m;
    pas = vll(n+1,-1);
    while(s<e){
        m = (s+e+1)/2;
        ll t = ski(m);
        if(t>a)e=m-1;
        else s=m;
    }
    vll v1(k), v2;
    vector<int> id;
    ll v3=-1;
    for(ll i = 0; i < k; ++i){v1[i] = ski(i+1);}
    for(ll i = max<ll>(1, s-k+1); i <= s; ++i){v2.pb(ski(i));id.pb(i);}
    if(s<n)v3=ski(s+1);
    ll p1=0, p2=0;
    for(ll i:v1)p1+=i;
    for(ll i:v2)p2+=i;
    if(p1>2*a)impossible();
    else if(k<=s){
        if(p2>=a){
            for(ll i = 0; i < k; ++i){
                if(p2<=2*a)break;
                id[i]=i+1;
                p2 += v1[i]-v2[i];
            }
            answer(id);
        }
        else if(s<n){
            iota(all(id),1);
            id.back()=s+1;
            if(p1-v1.back()+v3<=a*2)answer(id);
            else impossible();
        }
        else impossible();
    }
    else{
        iota(all(id),1);
        if(p1>=a)answer(id);
        else impossible();
    }
}


/*int main()
{
    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");
}
*/

• Subtask 1: 0 / 5
• Subtask 2: 0 / 15
• Subtask 3: 10 / 10
• Subtask 4: 15 / 15
• Subtask 5: 15 / 15
• Subtask 6: 20 / 20
• Subtask 7: 0 / 20