Submission #295240

#	Time	Username	Problem	Language	Result	Execution time	Memory
295240		erd1	Remittance (JOI19_remittance)	C++14	100 / 100	340 ms	36708 KiB

remittance

#include<bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define int lld
#define all(x) (x).begin(), (x).end()
using namespace std;
typedef int64_t lld;
typedef pair<int, int> pii;

template<size_t MOD>
struct S{
  static int mdu(int a){ return a < 0?a+MOD:a; }
  static int mdd(int a){ return a>=MOD?a-MOD:a; }
  static int invmod(int a, int b = MOD, int s0 = 0, int s1 = 1){
    return b?invmod(b, a%b, mdu(s1-(lld)(a/b)*s0%MOD), s0):s1;
  }
  int f, s;
  S(int a){ f = 0, s = a; }
  S(int a, int b){ f = a, s = b; }
  S operator+(S a){ return {mdd(f+a.f), mdd(s+a.s)}; }
  S operator-(S a){ return {mdu(f-a.f), mdu(s-a.s)}; }
  S operator/(int b){ return b = mdu(invmod(b)), S((lld)f*b%MOD, (lld)s*b%MOD); }
  friend ostream& operator<<(ostream& out, S a){ return out << a.f << "x + " << a.s; }
  int solve(){ return (lld)s*invmod(mdu(1-f))%MOD; }
};

const int md1 = 1000000007, md2 = 1000000009, md3 = 998244353;

vector<pii> v;
signed main(){ ios::sync_with_stdio(0); cin.tie(0);
  int n;
  cin >> n;
  S<md1> curgive1 = {1, 0};
  S<md2> curgive2 = {1, 0};
  //S<md3> curgive3 = {1, 0};
  lld suma = 0, sumb = 0;
  for(int i = 0; i < n; i++){
    int a, b;
    cin >> a >> b;
    v.pb({a, b});
    suma += a, sumb += b;
    curgive1 = (curgive1+a-b)/2;
    curgive2 = (curgive2+a-b)/2;
    //curgive3 = (curgive3+a-b)/2;
    //cout << curgive1 << endl << curgive2 << endl;
    //cout << curgive1.solve() << " " << curgive2.solve() << endl;
  }
  if(!sumb && suma)return cout << "No" << endl, 0;
  assert((curgive1.f != 1) && (curgive2.f != 1));
  if(curgive1.f == 1){
    return cout << "Yes" << endl, 0;
  }
  lld ans;
  /*
  if(curgive1.f == 1){
    if(curgive2.f == 1 || curgive3.f == 1)return cout << "No" << endl, 0;
    lld ans3 = curgive3.solve(), ans2 = curgive2.solve(); // a = ((lld)(ans2-ans1)*invmod(md1, md2)%md2+md2)%md2 (mod md2)
    ans = (lld)S<md2>::mdu((ans2-ans3)*S<md2>::invmod(md3)%md2)*md3+ans3;
  } else if(curgive2.f == 1) {
    lld ans1 = curgive1.solve(), ans3 = curgive3.solve(); // a = ((lld)(ans2-ans1)*invmod(md1, md2)%md2+md2)%md2 (mod md2)
    ans = (lld)S<md3>::mdu((ans3-ans1)*S<md3>::invmod(md1)%md3)*md1+ans1;
  } else if(curgive3.f == 1)
    return cout << "No" << endl, 0;
  else*/ {
    lld ans1 = curgive1.solve(), ans2 = curgive2.solve(); // a = ((lld)(ans2-ans1)*invmod(md1, md2)%md2+md2)%md2 (mod md2)
    ans = (lld)S<md2>::mdu((ans2-ans1)*S<md2>::invmod(md1)%md2)*md1+ans1;
    assert(ans%md1 == ans1 && ans%md2 == ans2);
  }
  //cout << ans << endl;
  lld curgive = ans;
  for(int i = 0; i < n; i++){
    curgive = curgive + v[i].ff-v[i].ss;
    //cout << curgive << endl;
    if(curgive<0 || (curgive&1))return cout << "No" << endl, 0;
    curgive /= 2;
  }
  if(curgive == ans)cout << "Yes" << endl;
  else cout << "No" << endl;
}
/*
5
0 0
1 0
2 3
3 3
4 0
*/

Compilation message (stderr)

remittance.cpp: In instantiation of 'static lld S<MOD>::mdd(lld) [with long unsigned int MOD = 1000000007; lld = long int]':
remittance.cpp:21:32:   required from 'S<MOD> S<MOD>::operator+(S<MOD>) [with long unsigned int MOD = 1000000007]'
remittance.cpp:43:26:   required from here
remittance.cpp:14:34: warning: comparison of integer expressions of different signedness: 'lld' {aka 'long int'} and 'long unsigned int' [-Wsign-compare]
   14 |   static int mdd(int a){ return a>=MOD?a-MOD:a; }
      |                                 ~^~~~~
remittance.cpp: In instantiation of 'static lld S<MOD>::mdd(lld) [with long unsigned int MOD = 1000000009; lld = long int]':
remittance.cpp:21:32:   required from 'S<MOD> S<MOD>::operator+(S<MOD>) [with long unsigned int MOD = 1000000009]'
remittance.cpp:44:26:   required from here
remittance.cpp:14:34: warning: comparison of integer expressions of different signedness: 'lld' {aka 'long int'} and 'long unsigned int' [-Wsign-compare]

• Subtask 1: 15 / 15
• Subtask 2: 40 / 40
• Subtask 3: 45 / 45