#include <bits/stdc++.h>
#include "books.h"
// #define int long long
// #define fi first
// #define se second
//
// #define sz(a) (int)((a).size())
// #define all(a) (a).begin(), (a).end()
//
// #define lsb(x) (x & (-x))
// #define vi vector<int>
// #define YES { cout << "YES" << endl; return; }
// #define NO { cout << "NO" << endl; return; }
// using ll = long long;
// using pii = std::pair<int, int>;
const int NMAX = 1e5;
using namespace std;
int64_t mins[NMAX + 5];
void solve(int N, int K, long long A, int S) {
int64_t mins[K];
for(int i = 0; i < K; i++)
mins[i] = skim(i + 1);
int64_t sum = 0;
for(int i = 0; i < K; i++)
sum += mins[i];
if(sum > 2 * A) {
impossible();
return;
}
if(sum >= A) {
vector<int> res;
for(int i = 0; i < K; i++)
res.push_back(i + 1);
answer(res);
return;
}
int lo = K, hi = N;
while(lo < hi){
int mid = (lo + hi) / 2;
int64_t x = skim(mid + 1);
if(x > A)
hi = mid;
else
lo = mid + 1;
}
if(lo < N){
int64_t big = skim(lo + 1);
sum = 0;
vector<int> res;
for(int i = 0; i < K - 1; i++) {
sum += mins[i];
res.push_back(i + 1);
}
sum += big;
res.push_back(lo + 1);
if(sum <= 2 * A){
answer(res);
return;
}
}
vector<pair<int, int64_t> > arr;
for(int i = 0; i < K; i++)
arr.push_back(make_pair(i, mins[i]));
for(int i = max(lo - K, K); i < lo; i++)
arr.push_back(make_pair(i, skim(i + 1)));
int n = arr.size();
sum = 0;
for(int i = n - K; i < n; i++)
sum += arr[i].second;
if(sum < A){
impossible();
return;
}
vector<int> res;
sum = 0;
for(int i = 0; i < K; i++){
sum += arr[i].second;
res.push_back(i);
}
for(int i = K - 1; i >= 0; i--){
int nxt = (i == K - 1 ? n : res[i+1]);
while(res[i] < nxt) {
if(sum >= A && sum <= 2 * A){
for(int j = 0; j < K; j++)
res[j] = arr[res[j]].first + 1;
answer(res);
return;
}
if(res[i] + 1 >= nxt)
break;
sum -= arr[res[i]].second;
++res[i];
sum += arr[res[i]].second;
}
}
impossible();
}
#ifndef ONLINE_JUDGE
/*
SAMPLE GRADER for task BOOKS
USAGE:
place together with your solution and books.h in the same directory, then:
g++ <flags> sample_grader.cpp <solution_file>
e.g.:
g++ -std=c++17 sample_grader.cpp books.cpp
INPUT/OUTPUT:
The sample grader expects on standard input two lines. The first line should
contain the four integers N, K, A and S. The second line should contain a list
of N integers, the sequence of difficulties x_1 x_2 ... x_N which has to be
strictly increasing. Then, the grader writes to standard output a protocol of
all grader functions called by your program.
At the end, the grader prints your verdict.
*/
#include<vector>
#include<cstdio>
#include<set>
#include<cstdlib>
#include<cstdarg>
#include<cassert>
#include"books.h"
using namespace std;
typedef long long ll;
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");
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", sUsed);
exit(0);
}
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");
}
#endif
