Submission #957123

#	Time	Username	Problem	Language	Result	Execution time	Memory
957123		DeltaStruct	Handcrafted Gift (IOI20_gift)	C++17	100 / 100	170 ms	28720 KiB

gift

#include "gift.h"
#include <bits/stdc++.h>
using namespace std;
 
int construct(int n,int m,vector<int> A,vector<int> B,vector<int> C){
  vector<int> D(n); iota(D.begin(),D.end(),0);
  for (int i(0);i < m;++i) if (C[i]==1) D[A[i]] = max(D[A[i]],B[i]);
  set<int> s; string r,u="RB"; int t=0;
  for (int i(0);i < n;++i){
    s.emplace(D[i]),r+=u[t];
    if (s.find(i)!=s.end()) s.erase(i);
    if (s.empty()) t^=1;
  }
  vector<int> acc(1); int cant = 0; for (char a:r) acc.emplace_back(acc.back()+(a=='B'));
  for (int i(0);i < m;++i) if (C[i]==2) if (acc[B[i]+1]-acc[A[i]]==0||acc[B[i]+1]-acc[A[i]]==B[i]-A[i]+1) cant = 1;
  if (cant) return 0;
  craft(r); return 1;
}

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 20 / 20
• Subtask 4: 25 / 25
• Subtask 5: 30 / 30