Submission #721169

#	Time	Username	Problem	Language	Result	Execution time	Memory
721169		FatihSolak	A Difficult(y) Choice (BOI21_books)	C++17	100 / 100	2 ms	296 KiB

books

#include <bits/stdc++.h>

#include "books.h"

using namespace std;
int cnt = 0;
long long get(int pos){
    assert(cnt++ <= 40);
    return skim(pos);
}
void solve(int n, int k, long long a, int s){
    int l = 1,r = n+1;
    while(l < r){
        int m = (l+r)/2;
        if(get(m) < a){
            l = m + 1;
        }
        else r = m;
    }
    vector<pair<int,long long>> x;
    vector<pair<int,long long>> y;
    for(int i = 1;i<=k;i++){
        x.push_back({i,get(i)});
    }
    if(l < k){
        impossible();
    }
    if(l != n+1){
        long long sum = get(l);
        for(int i = 0;i<k-1;i++){
            sum += x[i].second;
        }
        if(a <= sum && sum <= 2*a){
            vector<int> ret;
            for(int i = 1;i<=k-1;i++){
                ret.push_back(i);
            }
            ret.push_back(l);
            assert(ret.size()  == k);
            answer(ret);
        }
    }
    if(l == k){
        impossible();
    }
    for(int i = k;i>=1;i--){
        y.push_back({l-i,get(l-i)});
    }
    long long sum = 0;
    for(auto u:x){
        sum += u.second;
    }
    if(a <= sum && sum <= 2*a){
        vector<int> ret;
        for(int i = 1;i<=k;i++){
            ret.push_back(i);
        }
        assert(ret.size()  == k);
        answer(ret);
    }
    if(sum > 2*a){
        impossible();
    }
    for(int i = 1;i<=k;i++){
        sum -= x[k-i].second;
        sum += y[k-i].second;
        if(a <= sum && sum <= 2*a){
            vector<int> ret;
            for(int j = 1;j<=k-i;j++){
                ret.push_back(j);
            }
            for(int j = k-1;j>=k-i;j--){
                ret.push_back(y[j].first);
            }
            assert(ret.size()  == k);
            sort(ret.begin(),ret.end());
            answer(ret);
        }
        assert(sum < a);
    }
    impossible();
}

Compilation message (stderr)

In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from books.cpp:1:
books.cpp: In function 'void solve(int, int, long long int, int)':
books.cpp:39:32: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   39 |             assert(ret.size()  == k);
      |                    ~~~~~~~~~~~~^~~~
books.cpp:58:28: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   58 |         assert(ret.size()  == k);
      |                ~~~~~~~~~~~~^~~~
books.cpp:75:32: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   75 |             assert(ret.size()  == k);
      |                    ~~~~~~~~~~~~^~~~

• 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