Submission #982888

#	Time	Username	Problem	Language	Result	Execution time	Memory
982888		hyakup	Robots (IOI13_robots)	C++17	90 / 100	3039 ms	25052 KiB

robots

#include "robots.h"
#include <bits/stdc++.h>
using namespace std;

const int inf = 2e9 + 10;

vector<int> wbots, sbots;
struct Toy{
  int w, s; Toy( int w, int s ): w(w), s(s) {}
  bool operator < ( Toy t ){ return (( s == t.s ) ? w > t.w : s > t.s ); }
}; vector<Toy> toys;

bool check( int k ){
  multiset<pair<int, int>> s;
  for( int x : wbots ) s.insert({ x - 1, k });
  int i = 0;
  for( Toy cur : toys ){
    for( i; i < sbots.size() && sbots[i] > cur.s; i++ ) s.insert({ inf, k });
    auto it = s.lower_bound({ cur.w, 0 });
    if( it == s.end() ) return false;
    auto [val, qtd] = *it;
    s.erase(it);
    if( qtd > 1 ) s.insert({ val, qtd - 1 });
  }
  return true;
}

int bs(){
  int l = 1, r = toys.size() + 1;
  while( l < r ){
    int mid = ( l + r )/2;
    if( check(mid) ) r = mid;
    else l = mid + 1;
  }
  return ( r == toys.size() + 1 ) ? -1 : r;
}

int putaway(int A, int B, int T, int X[], int Y[], int W[], int S[]) {
  for( int i = 0; i < A; i++ ) wbots.push_back(X[i]);
  for( int i = 0; i < B; i++ ) sbots.push_back(Y[i]);
  for( int i = 0; i < T; i++ ) toys.push_back( Toy( W[i], S[i] ) );
  sort( wbots.begin(), wbots.end() );
  sort( sbots.rbegin(), sbots.rend() );
  sort( toys.begin(), toys.end() );
  return bs();
}

Compilation message (stderr)

robots.cpp: In function 'bool check(int)':
robots.cpp:18:10: warning: statement has no effect [-Wunused-value]
   18 |     for( i; i < sbots.size() && sbots[i] > cur.s; i++ ) s.insert({ inf, k });
      |          ^
robots.cpp:18:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |     for( i; i < sbots.size() && sbots[i] > cur.s; i++ ) s.insert({ inf, k });
      |             ~~^~~~~~~~~~~~~~
robots.cpp: In function 'int bs()':
robots.cpp:35:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Toy>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |   return ( r == toys.size() + 1 ) ? -1 : r;
      |            ~~^~~~~~~~~~~~~~~~~~

• Subtask 1: 14 / 14
• Subtask 2: 14 / 14
• Subtask 3: 25 / 25
• Subtask 4: 37 / 37
• Subtask 5: 0 / 10