oj.uz

Submission #825796

# Submission time Handle Problem Language Result Execution time Memory
825796 2023-08-15T08:11:12 Z GrindMachine Boat (APIO16_boat) C++17
36 / 100
 1179 ms 17468 KB 
// Om Namah Shivaya

#pragma GCC optimize("O3,unroll-loops")

#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;
}

ll choose[N*4][N], choose_ways[N*4][N], dp[N][N*2];

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);
    };

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

    rep(i,m){
        choose_ways[i][0] = 1;
        choose_ways[i][1] = choose[i][1];

        for(int j = 2; j <= n; ++j){
            // endpoints fixed i.e 2 of these j guys are always chosen
            // decide pick/ignore for rest j-2 guys
            rep(more,j-2+1){
                ll ways = ncr(j-2,more)*choose[i][more+2];
                choose_ways[i][j] += ways;
                choose_ways[i][j] %= MOD;
            }
        }
    }

    // ll dp[n+5][m+5];
    // memset(dp,0,sizeof dp);
    rep(j,m) 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++;
                    dp[i][j] += choose_ways[j][good]*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:32:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 | #define rep(i, n) for(int i = 0; i < n; ++i)
      |                                    ^
boat.cpp:120:5: note: in expansion of macro 'rep'
  120 |     rep(i,sz(b)){
      |     ^~~
boat.cpp:122:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  122 |         if(i+1 < sz(b)){
      |                ^

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 626 ms 12156 KB Output is correct
2 Correct 624 ms 12256 KB Output is correct
3 Correct 606 ms 12168 KB Output is correct
4 Correct 599 ms 12116 KB Output is correct
5 Correct 599 ms 12212 KB Output is correct
6 Correct 607 ms 12268 KB Output is correct
7 Correct 624 ms 12248 KB Output is correct
8 Correct 599 ms 12124 KB Output is correct
9 Correct 602 ms 12116 KB Output is correct
10 Correct 600 ms 12276 KB Output is correct
11 Correct 605 ms 12228 KB Output is correct
12 Correct 599 ms 12220 KB Output is correct
13 Correct 609 ms 12192 KB Output is correct
14 Correct 615 ms 12192 KB Output is correct
15 Correct 614 ms 12236 KB Output is correct
16 Correct 106 ms 4448 KB Output is correct
17 Correct 117 ms 4528 KB Output is correct
18 Correct 110 ms 4424 KB Output is correct
19 Correct 121 ms 4556 KB Output is correct
20 Correct 117 ms 4556 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 626 ms 12156 KB Output is correct
2 Correct 624 ms 12256 KB Output is correct
3 Correct 606 ms 12168 KB Output is correct
4 Correct 599 ms 12116 KB Output is correct
5 Correct 599 ms 12212 KB Output is correct
6 Correct 607 ms 12268 KB Output is correct
7 Correct 624 ms 12248 KB Output is correct
8 Correct 599 ms 12124 KB Output is correct
9 Correct 602 ms 12116 KB Output is correct
10 Correct 600 ms 12276 KB Output is correct
11 Correct 605 ms 12228 KB Output is correct
12 Correct 599 ms 12220 KB Output is correct
13 Correct 609 ms 12192 KB Output is correct
14 Correct 615 ms 12192 KB Output is correct
15 Correct 614 ms 12236 KB Output is correct
16 Correct 106 ms 4448 KB Output is correct
17 Correct 117 ms 4528 KB Output is correct
18 Correct 110 ms 4424 KB Output is correct
19 Correct 121 ms 4556 KB Output is correct
20 Correct 117 ms 4556 KB Output is correct
21 Incorrect 1179 ms 17468 KB Output isn't correct
22 Halted 0 ms 0 KB -

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 4204 KB Output is correct
2 Correct 12 ms 4180 KB Output is correct
3 Correct 13 ms 4180 KB Output is correct
4 Correct 13 ms 4212 KB Output is correct
5 Correct 13 ms 4108 KB Output is correct
6 Correct 14 ms 4180 KB Output is correct
7 Correct 15 ms 4200 KB Output is correct
8 Correct 15 ms 4180 KB Output is correct
9 Correct 14 ms 4148 KB Output is correct
10 Correct 14 ms 4180 KB Output is correct
11 Correct 14 ms 4180 KB Output is correct
12 Correct 13 ms 4212 KB Output is correct
13 Correct 13 ms 4096 KB Output is correct
14 Correct 13 ms 4172 KB Output is correct
15 Correct 13 ms 4192 KB Output is correct
16 Correct 6 ms 2260 KB Output is correct
17 Correct 6 ms 2260 KB Output is correct
18 Correct 6 ms 2260 KB Output is correct
19 Correct 6 ms 2260 KB Output is correct
20 Correct 6 ms 2260 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 626 ms 12156 KB Output is correct
2 Correct 624 ms 12256 KB Output is correct
3 Correct 606 ms 12168 KB Output is correct
4 Correct 599 ms 12116 KB Output is correct
5 Correct 599 ms 12212 KB Output is correct
6 Correct 607 ms 12268 KB Output is correct
7 Correct 624 ms 12248 KB Output is correct
8 Correct 599 ms 12124 KB Output is correct
9 Correct 602 ms 12116 KB Output is correct
10 Correct 600 ms 12276 KB Output is correct
11 Correct 605 ms 12228 KB Output is correct
12 Correct 599 ms 12220 KB Output is correct
13 Correct 609 ms 12192 KB Output is correct
14 Correct 615 ms 12192 KB Output is correct
15 Correct 614 ms 12236 KB Output is correct
16 Correct 106 ms 4448 KB Output is correct
17 Correct 117 ms 4528 KB Output is correct
18 Correct 110 ms 4424 KB Output is correct
19 Correct 121 ms 4556 KB Output is correct
20 Correct 117 ms 4556 KB Output is correct
21 Incorrect 1179 ms 17468 KB Output isn't correct
22 Halted 0 ms 0 KB -