oj.uz

Submission #699553

# Submission time Handle Problem Language Result Execution time Memory
699553 2023-02-17T11:46:49 Z Abrar_Al_Samit Boat (APIO16_boat) C++17
0 / 100
 2000 ms 1364 KB 
#include<bits/stdc++.h>
using namespace std;

const int nax = 503;
const int mod = 1e9 + 7;

vector<int>ind[nax];
int a[nax], b[nax];
int n, m;
int dp[nax][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 C(int n, int r) {
  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, quickpow(i, mod-2));
  }
  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 = solve(i+1, ind[i][mx]);
    for(int take=0; take<=min(cur_op, len-1); ++take) {
      ret = add(ret, mul(cur, mul(C(cur_op, take), C(len, take+1))));
    }
    cur_op++;
  }
  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);
      }
    }
  }
  // for(int i=0; i<m; ++i) {
  //   cerr<<imp[i]<<' ';
  // } cerr<<endl;
  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;
}

Compilation message

boat.cpp: In function 'int solve(int, int)':
boat.cpp:50:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |   for(int mx=0, cur_op=0; mx<ind[i].size(); ++mx) {
      |                           ~~^~~~~~~~~~~~~~

Subtask #1
0 / 9.0

# Verdict Execution time Memory Grader output
1 Runtime error 2 ms 980 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Runtime error 2 ms 980 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Execution timed out 2082 ms 1364 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Runtime error 2 ms 980 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -