oj.uz

Submission #825658

# Submission time Handle Problem Language Result Execution time Memory
825658 2023-08-15T06:55:31 Z GrindMachine Boat (APIO16_boat) C++17
36 / 100
 2000 ms 13524 KB 
// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*



*/

const int MOD = 1e9 + 7;
const int N = 500 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

ll fact[N], ifact[N];

ll bexp(ll a, ll b) {
    a %= MOD;
    if (a == 0) return 0;

    ll res = 1;

    while (b) {
        if (b & 1) res = res * a % MOD;
        a = a * a % MOD;
        b >>= 1;
    }

    return res;
}

ll invmod(ll a) {
    return bexp(a, MOD - 2);
}

ll ncr(ll n, ll r) {
    if (n < 0 or r < 0 or n < r) return 0;
    return fact[n] * ifact[r] % MOD * ifact[n - r] % MOD;
}

ll npr(ll n, ll r) {
    if (n < 0 or r < 0 or n < r) return 0;
    return fact[n] * ifact[n - r] % MOD;
}

void precalc(ll n) {
    fact[0] = 1;
    rep1(i, n) fact[i] = fact[i - 1] * i % MOD;

    ifact[n] = invmod(fact[n]);
    rev(i, n - 1, 0) ifact[i] = ifact[i + 1] * (i + 1) % MOD;
}

void solve(int test_case)
{
    precalc(N-1);

    ll n; cin >> n;
    vector<pll> a(n+5);
    rep1(i,n) cin >> a[i].ff >> a[i].ss;

    vector<ll> b;
    rep1(i,n) b.pb(a[i].ff), b.pb(a[i].ss);
    sort(all(b));
    b.resize(unique(all(b))-b.begin());

    vector<pll> ranges;
    ranges.pb({0,0});
    rep(i,sz(b)){
        ranges.pb({b[i],b[i]});
        if(i+1 < sz(b)){
            if(b[i]+1 <= b[i+1]-1){
                ranges.pb({b[i]+1,b[i+1]-1});
            }   
        }
    }

    ll m = sz(ranges);

    ll choose[m+5][n+5];
    memset(choose,0,sizeof choose);

    rep(i,m){
        auto [l,r] = ranges[i];
        ll len = r-l+1;
        choose[i][0] = 1;
        ll curr = 1;

        rep1(r,n){
            if(len < r) break;
            curr = curr * (len-r+1) % MOD;
            choose[i][r] = curr * ifact[r] % MOD;
        }
    }

    auto isect = [&](pll p1, pll p2){
        return max(p1.ff,p2.ff) <= min(p1.ss,p2.ss);
    };

    // debug(ranges);
    // debug(choose[2][1]);

    ll dp[n+5][m+5];
    memset(dp,0,sizeof dp);
    rep(j,m+5) dp[0][j] = 1;

    rep1(i,n){
        dp[i][0] = 1;
        rep1(j,m-1){
            dp[i][j] = (dp[i-1][j]+dp[i][j-1]-dp[i-1][j-1]+MOD)%MOD;
            if(!isect(a[i],ranges[j])) conts;

            dp[i][j] += choose[j][1]*dp[i-1][j-1];
            dp[i][j] %= MOD;

            ll good = 1;

            rev(k,i-1,1){
                // i and k fixed
                // few more in between
                if(isect(a[k],ranges[j])){
                    good++;
                    rep(more,good-2+1){
                        ll choose_guys = ncr(good-2,more);
                        ll choose_points = choose[j][more+2];
                        ll choose_ways = choose_guys*choose_points % MOD;
                        dp[i][j] += choose_ways*dp[k-1][j-1];
                        dp[i][j] %= MOD;
                    }
                }
            }
        }
    }

    ll ans = (dp[n][m-1]-1+MOD)%MOD;
    cout << ans << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

Compilation message

boat.cpp: In function 'void solve(int)':
boat.cpp:30:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 | #define rep(i, n) for(int i = 0; i < n; ++i)
      |                                    ^
boat.cpp:116:5: note: in expansion of macro 'rep'
  116 |     rep(i,sz(b)){
      |     ^~~
boat.cpp:118:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  118 |         if(i+1 < sz(b)){
      |                ^

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 8276 KB Output is correct
2 Correct 8 ms 8316 KB Output is correct
3 Correct 8 ms 8256 KB Output is correct
4 Correct 8 ms 8220 KB Output is correct
5 Correct 8 ms 8276 KB Output is correct
6 Correct 8 ms 8276 KB Output is correct
7 Correct 8 ms 8316 KB Output is correct
8 Correct 8 ms 8276 KB Output is correct
9 Correct 8 ms 8276 KB Output is correct
10 Correct 8 ms 8276 KB Output is correct
11 Correct 8 ms 8276 KB Output is correct
12 Correct 8 ms 8244 KB Output is correct
13 Correct 8 ms 8276 KB Output is correct
14 Correct 8 ms 8276 KB Output is correct
15 Correct 8 ms 8320 KB Output is correct
16 Correct 2 ms 1748 KB Output is correct
17 Correct 2 ms 1876 KB Output is correct
18 Correct 2 ms 1748 KB Output is correct
19 Correct 2 ms 1876 KB Output is correct
20 Correct 2 ms 1748 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 8276 KB Output is correct
2 Correct 8 ms 8316 KB Output is correct
3 Correct 8 ms 8256 KB Output is correct
4 Correct 8 ms 8220 KB Output is correct
5 Correct 8 ms 8276 KB Output is correct
6 Correct 8 ms 8276 KB Output is correct
7 Correct 8 ms 8316 KB Output is correct
8 Correct 8 ms 8276 KB Output is correct
9 Correct 8 ms 8276 KB Output is correct
10 Correct 8 ms 8276 KB Output is correct
11 Correct 8 ms 8276 KB Output is correct
12 Correct 8 ms 8244 KB Output is correct
13 Correct 8 ms 8276 KB Output is correct
14 Correct 8 ms 8276 KB Output is correct
15 Correct 8 ms 8320 KB Output is correct
16 Correct 2 ms 1748 KB Output is correct
17 Correct 2 ms 1876 KB Output is correct
18 Correct 2 ms 1748 KB Output is correct
19 Correct 2 ms 1876 KB Output is correct
20 Correct 2 ms 1748 KB Output is correct
21 Execution timed out 2078 ms 13524 KB Time limit exceeded
22 Halted 0 ms 0 KB -

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 30 ms 980 KB Output is correct
2 Correct 18 ms 1008 KB Output is correct
3 Correct 32 ms 992 KB Output is correct
4 Correct 31 ms 980 KB Output is correct
5 Correct 35 ms 980 KB Output is correct
6 Correct 122 ms 988 KB Output is correct
7 Correct 124 ms 980 KB Output is correct
8 Correct 121 ms 992 KB Output is correct
9 Correct 121 ms 988 KB Output is correct
10 Correct 125 ms 984 KB Output is correct
11 Correct 47 ms 984 KB Output is correct
12 Correct 20 ms 980 KB Output is correct
13 Correct 29 ms 980 KB Output is correct
14 Correct 28 ms 1000 KB Output is correct
15 Correct 40 ms 984 KB Output is correct
16 Correct 19 ms 708 KB Output is correct
17 Correct 14 ms 624 KB Output is correct
18 Correct 13 ms 596 KB Output is correct
19 Correct 11 ms 628 KB Output is correct
20 Correct 17 ms 596 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 8276 KB Output is correct
2 Correct 8 ms 8316 KB Output is correct
3 Correct 8 ms 8256 KB Output is correct
4 Correct 8 ms 8220 KB Output is correct
5 Correct 8 ms 8276 KB Output is correct
6 Correct 8 ms 8276 KB Output is correct
7 Correct 8 ms 8316 KB Output is correct
8 Correct 8 ms 8276 KB Output is correct
9 Correct 8 ms 8276 KB Output is correct
10 Correct 8 ms 8276 KB Output is correct
11 Correct 8 ms 8276 KB Output is correct
12 Correct 8 ms 8244 KB Output is correct
13 Correct 8 ms 8276 KB Output is correct
14 Correct 8 ms 8276 KB Output is correct
15 Correct 8 ms 8320 KB Output is correct
16 Correct 2 ms 1748 KB Output is correct
17 Correct 2 ms 1876 KB Output is correct
18 Correct 2 ms 1748 KB Output is correct
19 Correct 2 ms 1876 KB Output is correct
20 Correct 2 ms 1748 KB Output is correct
21 Execution timed out 2078 ms 13524 KB Time limit exceeded
22 Halted 0 ms 0 KB -