Submission #994625

#	Time	Username	Problem	Language	Result	Execution time	Memory
994625		jonathanirvings	Trains (BOI24_trains)	C++17	100 / 100	737 ms	80720 KiB

Main

//start of jonathanirvings' template v3.0.3 (BETA)

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

typedef long long LL;
typedef pair<int,int> pii;
typedef pair<LL,LL> pll;
typedef pair<string,string> pss;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pii> vii;
typedef vector<LL> vl;
typedef vector<vl> vvl;

double EPS = 1e-9;
int INF = 1000000005;
long long INFF = 1000000000000000005LL;
double PI = acos(-1);
int dirx[8] = {-1,0,0,1,-1,-1,1,1};
int diry[8] = {0,1,-1,0,-1,1,-1,1};

#ifdef TESTING
  #define DEBUG fprintf(stderr,"====TESTING====\n")
  #define VALUE(x) cerr << "The value of " << #x << " is " << x << endl
  #define debug(...) fprintf(stderr, __VA_ARGS__)
#else
  #define DEBUG
  #define VALUE(x)
  #define debug(...)
#endif

#define FOR(a,b,c) for (int (a)=(b);(a)<(c);++(a))
#define FORN(a,b,c) for (int (a)=(b);(a)<=(c);++(a))
#define FORD(a,b,c) for (int (a)=(b);(a)>=(c);--(a))
#define FORSQ(a,b,c) for (int (a)=(b);(a)*(a)<=(c);++(a))
#define FORC(a,b,c) for (char (a)=(b);(a)<=(c);++(a))
#define FOREACH(a,b) for (auto &(a) : (b))
#define REP(i,n) FOR(i,0,n)
#define REPN(i,n) FORN(i,1,n)
#define MAX(a,b) a = max(a,b)
#define MIN(a,b) a = min(a,b)
#define SQR(x) ((LL)(x) * (x))
#define RESET(a,b) memset(a,b,sizeof(a))
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define ALL(v) v.begin(),v.end()
#define ALLA(arr,sz) arr,arr+sz
#define SIZE(v) (int)v.size()
#define SORT(v) sort(ALL(v))
#define REVERSE(v) reverse(ALL(v))
#define SORTA(arr,sz) sort(ALLA(arr,sz))
#define REVERSEA(arr,sz) reverse(ALLA(arr,sz))
#define PERMUTE next_permutation
#define TC(t) while(t--)

inline string IntToString(LL a){
  char x[100];
  sprintf(x,"%lld",a); string s = x;
  return s;
}

inline LL StringToInt(string a){
  char x[100]; LL res;
  strcpy(x,a.c_str()); sscanf(x,"%lld",&res);
  return res;
}

inline string GetString(void){
  char x[1000005];
  scanf("%s",x); string s = x;
  return s;
}

inline string uppercase(string s){
  int n = SIZE(s);
  REP(i,n) if (s[i] >= 'a' && s[i] <= 'z') s[i] = s[i] - 'a' + 'A';
  return s;
}

inline string lowercase(string s){
  int n = SIZE(s);
  REP(i,n) if (s[i] >= 'A' && s[i] <= 'Z') s[i] = s[i] - 'A' + 'a';
  return s;
}

inline void OPEN (string s) {
  #ifndef TESTING
  freopen ((s + ".in").c_str (), "r", stdin);
  freopen ((s + ".out").c_str (), "w", stdout);
  #endif
}

//end of jonathanirvings' template v3.0.3 (BETA)

#ifndef ATCODER_FENWICKTREE_HPP
#define ATCODER_FENWICKTREE_HPP 1

#include <cassert>
#include <vector>

#ifndef ATCODER_INTERNAL_TYPE_TRAITS_HPP
#define ATCODER_INTERNAL_TYPE_TRAITS_HPP 1

#include <cassert>
#include <numeric>
#include <type_traits>

namespace atcoder {

namespace internal {

#ifndef _MSC_VER
template <class T>
using is_signed_int128 =
    typename std::conditional<std::is_same<T, __int128_t>::value ||
                                  std::is_same<T, __int128>::value,
                              std::true_type,
                              std::false_type>::type;

template <class T>
using is_unsigned_int128 =
    typename std::conditional<std::is_same<T, __uint128_t>::value ||
                                  std::is_same<T, unsigned __int128>::value,
                              std::true_type,
                              std::false_type>::type;

template <class T>
using make_unsigned_int128 =
    typename std::conditional<std::is_same<T, __int128_t>::value,
                              __uint128_t,
                              unsigned __int128>;

template <class T>
using is_integral = typename std::conditional<std::is_integral<T>::value ||
                                                  is_signed_int128<T>::value ||
                                                  is_unsigned_int128<T>::value,
                                              std::true_type,
                                              std::false_type>::type;

template <class T>
using is_signed_int = typename std::conditional<(is_integral<T>::value &&
                                                 std::is_signed<T>::value) ||
                                                    is_signed_int128<T>::value,
                                                std::true_type,
                                                std::false_type>::type;

template <class T>
using is_unsigned_int =
    typename std::conditional<(is_integral<T>::value &&
                               std::is_unsigned<T>::value) ||
                                  is_unsigned_int128<T>::value,
                              std::true_type,
                              std::false_type>::type;

template <class T>
using to_unsigned = typename std::conditional<
    is_signed_int128<T>::value,
    make_unsigned_int128<T>,
    typename std::conditional<std::is_signed<T>::value,
                              std::make_unsigned<T>,
                              std::common_type<T>>::type>::type;

#else

template <class T> using is_integral = typename std::is_integral<T>;

template <class T>
using is_signed_int =
    typename std::conditional<is_integral<T>::value && std::is_signed<T>::value,
                              std::true_type,
                              std::false_type>::type;

template <class T>
using is_unsigned_int =
    typename std::conditional<is_integral<T>::value &&
                                  std::is_unsigned<T>::value,
                              std::true_type,
                              std::false_type>::type;

template <class T>
using to_unsigned = typename std::conditional<is_signed_int<T>::value,
                                              std::make_unsigned<T>,
                                              std::common_type<T>>::type;

#endif

template <class T>
using is_signed_int_t = std::enable_if_t<is_signed_int<T>::value>;

template <class T>
using is_unsigned_int_t = std::enable_if_t<is_unsigned_int<T>::value>;

template <class T> using to_unsigned_t = typename to_unsigned<T>::type;

}  // namespace internal

}  // namespace atcoder

#endif  // ATCODER_INTERNAL_TYPE_TRAITS_HPP

namespace atcoder {

// Reference: https://en.wikipedia.org/wiki/Fenwick_tree
template <class T> struct fenwick_tree {
    using U = internal::to_unsigned_t<T>;

  public:
    fenwick_tree() : _n(0) {}
    explicit fenwick_tree(int n) : _n(n), data(n) {}

    void add(int p, T x) {
        assert(0 <= p && p < _n);
        p++;
        while (p <= _n) {
            data[p - 1] += U(x);
            p += p & -p;
        }
    }

    T sum(int l, int r) {
        assert(0 <= l && l <= r && r <= _n);
        return sum(r) - sum(l);
    }

  private:
    int _n;
    std::vector<U> data;

    U sum(int r) {
        U s = 0;
        while (r > 0) {
            s += data[r - 1];
            r -= r & -r;
        }
        return s;
    }
};

}  // namespace atcoder

#endif  // ATCODER_FENWICKTREE_HPP

template <int Mod>
struct ModInt {
  
  ModInt() : num_(0) {}
 
  template <class T>
  ModInt(T num) {
    long long x = (long long)(num % (long long)(Mod));
    if (x < 0) x += Mod;
    num_ = (int)(x);
  }
 
  ModInt& operator++() {
    num_++;
    if (num_ == Mod) num_ = 0;
    return *this;
  }
  ModInt& operator--() {
    if (num_ == 0) num_ = Mod;
    num_--;
    return *this;
  }
  ModInt operator++(int) {
    ModInt result = *this;
    ++*this;
    return result;
  }
  ModInt operator--(int) {
    ModInt result = *this;
    --*this;
    return result;
  }
 
  ModInt& operator+=(const ModInt& rhs) {
    num_ += rhs.num_;
    if (num_ >= Mod) num_ -= Mod;
    return *this;
  }
  ModInt& operator-=(const ModInt& rhs) {
    num_ -= rhs.num_;
    if (num_ < 0) num_ += Mod;
    return *this;
  }
  ModInt& operator*=(const ModInt& rhs) {
    long long z = num_;
    z *= rhs.num_;
    num_ = (int)(z % Mod);
    return *this;
  }
  ModInt& operator/=(const ModInt& rhs) { return *this = *this * rhs.inv(); }
 
  ModInt operator+() const { return *this; }
  ModInt operator-() const { return ModInt() - *this; }
 
  ModInt pow(long long n) const {
    assert(0 <= n);
    ModInt x = *this, r = 1;
    while (n) {
      if (n & 1) r *= x;
      x *= x;
      n >>= 1;
    }
    return r;
  }
  ModInt inv() const {
    return pow(Mod - 2);
  }
 
  friend ModInt operator+(const ModInt& lhs, const ModInt& rhs) {
    return ModInt(lhs) += rhs;
  }
  friend ModInt operator-(const ModInt& lhs, const ModInt& rhs) {
    return ModInt(lhs) -= rhs;
  }
  friend ModInt operator*(const ModInt& lhs, const ModInt& rhs) {
    return ModInt(lhs) *= rhs;
  }
  friend ModInt operator/(const ModInt& lhs, const ModInt& rhs) {
    return ModInt(lhs) /= rhs;
  }
  friend bool operator==(const ModInt& lhs, const ModInt& rhs) {
    return lhs.num_ == rhs.num_;
  }
  friend bool operator!=(const ModInt& lhs, const ModInt& rhs) {
    return lhs.num_ != rhs.num_;
  }
 
  int get() const { return num_; }
 
  int num_;
};
 
template <int Mod>
struct ModBinomCoeff {
 
  ModBinomCoeff() {}
  ModBinomCoeff(int N) : fact_(N + 1), inv_fact_(N + 1) {
    fact_[0] = 1;
    for (int i = 1; i <= N; ++i) {
      fact_[i] = fact_[i - 1] * (i);
    }
    inv_fact_[N] = fact_[N].inv();
    for (int i = N - 1; i >= 0; --i) {
      inv_fact_[i] = inv_fact_[i + 1] * (i + 1);
    }
  }
 
  ModInt<Mod> fact(int N) {
    assert(N < fact_.size());
    return fact_[N];
  }
  ModInt<Mod> choose(int N, int K) {
    assert(N < fact_.size());
    return fact_[N] * inv_fact_[K] * inv_fact_[N - K];
  }
 
  vector<ModInt<Mod>> fact_;
  vector<ModInt<Mod>> inv_fact_;
};
 
constexpr int Mod998244353 = 998244353;
constexpr int Mod1000000007 = 1000000007;
constexpr int Mod = Mod1000000007;
 
using Int = ModInt<Mod>;
using BinomCoeff = ModBinomCoeff<Mod>;

using Fenwick = atcoder::fenwick_tree<Int>;

int LIMIT = 200;

int n;
int d[100005];
int x[100005];
Int dp[100005];
vector<vector<Fenwick>> fenwick;

int main()
{
  scanf("%d",&n);
  REP(i,n) scanf("%d %d",&d[i],&x[i]);
  fenwick.resize(LIMIT);
  FOR(delta,1,LIMIT) 
  {
    fenwick[delta].resize(delta);
    REP(i,delta) fenwick[delta][i] = Fenwick(n / delta + 3);
  }
  FORD(i,n-1,0)
  {
    // debug("%d\n",i);
    dp[i] = 1;
    if (d[i] >= LIMIT)
    {
      FORN(t,1,x[i])
      {
        if (i + d[i] * t >= n) break;
        dp[i] += dp[i + d[i] * t];
      }
    } else if (d[i] > 0)
    {
      int l = i / d[i];
      int r = min(n / d[i] + 3, l + x[i] + 1);
      dp[i] += fenwick[d[i]][i % d[i]].sum(l,r);
    }
    FOR(delta,1,LIMIT) fenwick[delta][i % delta].add(i / delta,dp[i]);
  }
  printf("%d\n",dp[0].get());
}

Compilation message (stderr)

Main.cpp: In function 'std::string uppercase(std::string)':
Main.cpp:33:29: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   33 | #define FOR(a,b,c) for (int (a)=(b);(a)<(c);++(a))
      |                             ^
Main.cpp:39:18: note: in expansion of macro 'FOR'
   39 | #define REP(i,n) FOR(i,0,n)
      |                  ^~~
Main.cpp:79:3: note: in expansion of macro 'REP'
   79 |   REP(i,n) if (s[i] >= 'a' && s[i] <= 'z') s[i] = s[i] - 'a' + 'A';
      |   ^~~
Main.cpp: In function 'std::string lowercase(std::string)':
Main.cpp:33:29: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   33 | #define FOR(a,b,c) for (int (a)=(b);(a)<(c);++(a))
      |                             ^
Main.cpp:39:18: note: in expansion of macro 'FOR'
   39 | #define REP(i,n) FOR(i,0,n)
      |                  ^~~
Main.cpp:85:3: note: in expansion of macro 'REP'
   85 |   REP(i,n) if (s[i] >= 'A' && s[i] <= 'Z') s[i] = s[i] - 'A' + 'a';
      |   ^~~
Main.cpp: In function 'int main()':
Main.cpp:33:29: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   33 | #define FOR(a,b,c) for (int (a)=(b);(a)<(c);++(a))
      |                             ^
Main.cpp:39:18: note: in expansion of macro 'FOR'
   39 | #define REP(i,n) FOR(i,0,n)
      |                  ^~~
Main.cpp:386:3: note: in expansion of macro 'REP'
  386 |   REP(i,n) scanf("%d %d",&d[i],&x[i]);
      |   ^~~
Main.cpp:33:29: warning: unnecessary parentheses in declaration of 'delta' [-Wparentheses]
   33 | #define FOR(a,b,c) for (int (a)=(b);(a)<(c);++(a))
      |                             ^
Main.cpp:388:3: note: in expansion of macro 'FOR'
  388 |   FOR(delta,1,LIMIT)
      |   ^~~
Main.cpp:33:29: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   33 | #define FOR(a,b,c) for (int (a)=(b);(a)<(c);++(a))
      |                             ^
Main.cpp:39:18: note: in expansion of macro 'FOR'
   39 | #define REP(i,n) FOR(i,0,n)
      |                  ^~~
Main.cpp:391:5: note: in expansion of macro 'REP'
  391 |     REP(i,delta) fenwick[delta][i] = Fenwick(n / delta + 3);
      |     ^~~
Main.cpp:35:30: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   35 | #define FORD(a,b,c) for (int (a)=(b);(a)>=(c);--(a))
      |                              ^
Main.cpp:393:3: note: in expansion of macro 'FORD'
  393 |   FORD(i,n-1,0)
      |   ^~~~
Main.cpp:34:30: warning: unnecessary parentheses in declaration of 't' [-Wparentheses]
   34 | #define FORN(a,b,c) for (int (a)=(b);(a)<=(c);++(a))
      |                              ^
Main.cpp:399:7: note: in expansion of macro 'FORN'
  399 |       FORN(t,1,x[i])
      |       ^~~~
Main.cpp:33:29: warning: unnecessary parentheses in declaration of 'delta' [-Wparentheses]
   33 | #define FOR(a,b,c) for (int (a)=(b);(a)<(c);++(a))
      |                             ^
Main.cpp:410:5: note: in expansion of macro 'FOR'
  410 |     FOR(delta,1,LIMIT) fenwick[delta][i % delta].add(i / delta,dp[i]);
      |     ^~~
Main.cpp:385:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  385 |   scanf("%d",&n);
      |   ~~~~~^~~~~~~~~
Main.cpp:386:17: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  386 |   REP(i,n) scanf("%d %d",&d[i],&x[i]);
      |            ~~~~~^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 13 / 13
• Subtask 3: 16 / 16
• Subtask 4: 34 / 34
• Subtask 5: 29 / 29