제출 #699585

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
699585		Abrar_Al_Samit	Boat (APIO16_boat)	C++17	58 / 100	962 ms	119144 KiB

boat

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

const int nax = 503;
const int mod = 1e9 + 7;
const int cax = 1e6 + 3;
const long long sux = 1361;

vector<int>ind[nax*2];
int a[nax], b[nax];
int n, m;
int dp[nax*2][nax];
int inv[nax];
vector<int>imp;

int add(int a, int b) {
  a += b;
  if(a>=mod) a -= mod;
  return a;
}
int mul(int a, int b) {
  return (a * 1LL * b) % mod;
}
int quickpow(int a, int b) {
  int ret = 1;
  while(b) {
    if(b&1) ret = mul(ret, a);
    a = mul(a, a);
    b >>= 1;
  }
  return ret;
}

int get(int x) {
  int &ret = inv[x];
  if(ret==-1) {
    ret = quickpow(x, mod-2);
  }
  return ret;
}
vector<pair<long long,int>>table[cax];
int C(int n, int r) {
  long long H = n * sux + r;
  int H2 = H % cax;
  for(auto x : table[H2]) {
    if(x.first==H) return x.second;
  }


  int ret = 1;
  for(int i=n-r+1; i<=n; ++i) {
    ret = mul(ret, i);
  }
  for(int i=1; i<=r; ++i) {
    ret = mul(ret, get(i));
  }
  table[H2].emplace_back(H, ret);
  assert((int)table[H2].size()<=3);
  return ret;
}

vector<pair<long long,int>>andp[cax];
int get(int len, int op) {
  long long H = len * sux + op;
  int H2 = H % cax;
  for(auto x : andp[H2]) {
    if(x.first==H) return x.second;
  }

  int ret = 0;
  for(int take=0; take<=min(op, len-1); ++take) {
    ret = add(ret, mul(C(op, take), C(len, take+1)));
  }

  andp[H2].emplace_back(H, ret);
  assert((int)andp[H2].size()<=3);
  return ret;
}
int solve(int i, int prv) {
  if(i==m-1) return prv>0;
  int &ret = dp[i][prv];
  if(ret!=-1) return ret;
  ret = 0;

  ret = solve(i+1, prv);
  int len = imp[i+1]-imp[i];

  for(int mx=0, cur_op=0; mx<ind[i].size(); ++mx) {
    if(ind[i][mx]<=prv) continue;

    int cur = mul(solve(i+1, ind[i][mx]), get(len, cur_op));
    cur_op++;
    ret = add(ret, cur);
  }
  return ret;
}
void PlayGround() {
  cin>>n;
  set<int>pts;
  for(int i=1; i<=n; ++i) {
    cin>>a[i]>>b[i];
    pts.insert(a[i]);
    pts.insert(b[i]+1);
  }

  for(int x : pts) {
    imp.push_back(x);
  } 
  m = imp.size();
  for(int i=0; i<m; ++i) {
    for(int j=1; j<=n; ++j) {
      if(imp[i]>=a[j] && imp[i]<=b[j]) {
        ind[i].push_back(j);
      }
    }
  }
  memset(inv, -1, sizeof inv);
  memset(dp, -1, sizeof dp);
  cout<<solve(0, 0)<<'\n';


  // cerr << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  PlayGround();
  return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

boat.cpp: In function 'int solve(int, int)':
boat.cpp:88:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   88 |   for(int mx=0, cur_op=0; mx<ind[i].size(); ++mx) {
      |                           ~~^~~~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 22 / 22
• Subtask 3: 27 / 27
• Subtask 4: 0 / 42