oj.uz

Submission #825794

# Submission time Handle Problem Language Result Execution time Memory
825794 2023-08-15T08:10:15 Z GrindMachine Boat (APIO16_boat) C++17
36 / 100
 634 ms 12260 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*2][N], choose_ways[N*2][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 614 ms 12224 KB Output is correct
2 Correct 599 ms 12140 KB Output is correct
3 Correct 611 ms 12164 KB Output is correct
4 Correct 612 ms 12224 KB Output is correct
5 Correct 601 ms 12204 KB Output is correct
6 Correct 606 ms 12168 KB Output is correct
7 Correct 613 ms 12208 KB Output is correct
8 Correct 628 ms 12180 KB Output is correct
9 Correct 617 ms 12216 KB Output is correct
10 Correct 620 ms 12176 KB Output is correct
11 Correct 618 ms 12220 KB Output is correct
12 Correct 615 ms 12260 KB Output is correct
13 Correct 607 ms 12240 KB Output is correct
14 Correct 606 ms 12148 KB Output is correct
15 Correct 634 ms 12200 KB Output is correct
16 Correct 108 ms 4372 KB Output is correct
17 Correct 117 ms 4588 KB Output is correct
18 Correct 109 ms 4532 KB Output is correct
19 Correct 124 ms 4512 KB Output is correct
20 Correct 111 ms 4424 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 614 ms 12224 KB Output is correct
2 Correct 599 ms 12140 KB Output is correct
3 Correct 611 ms 12164 KB Output is correct
4 Correct 612 ms 12224 KB Output is correct
5 Correct 601 ms 12204 KB Output is correct
6 Correct 606 ms 12168 KB Output is correct
7 Correct 613 ms 12208 KB Output is correct
8 Correct 628 ms 12180 KB Output is correct
9 Correct 617 ms 12216 KB Output is correct
10 Correct 620 ms 12176 KB Output is correct
11 Correct 618 ms 12220 KB Output is correct
12 Correct 615 ms 12260 KB Output is correct
13 Correct 607 ms 12240 KB Output is correct
14 Correct 606 ms 12148 KB Output is correct
15 Correct 634 ms 12200 KB Output is correct
16 Correct 108 ms 4372 KB Output is correct
17 Correct 117 ms 4588 KB Output is correct
18 Correct 109 ms 4532 KB Output is correct
19 Correct 124 ms 4512 KB Output is correct
20 Correct 111 ms 4424 KB Output is correct
21 Runtime error 6 ms 8660 KB Execution killed with signal 11
22 Halted 0 ms 0 KB -

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 4192 KB Output is correct
2 Correct 12 ms 4220 KB Output is correct
3 Correct 13 ms 4212 KB Output is correct
4 Correct 13 ms 4140 KB Output is correct
5 Correct 14 ms 4124 KB Output is correct
6 Correct 14 ms 4216 KB Output is correct
7 Correct 14 ms 4180 KB Output is correct
8 Correct 14 ms 4108 KB Output is correct
9 Correct 14 ms 4180 KB Output is correct
10 Correct 18 ms 4104 KB Output is correct
11 Correct 14 ms 4180 KB Output is correct
12 Correct 13 ms 4180 KB Output is correct
13 Correct 13 ms 4180 KB Output is correct
14 Correct 13 ms 4200 KB Output is correct
15 Correct 13 ms 4132 KB Output is correct
16 Correct 6 ms 2260 KB Output is correct
17 Correct 6 ms 2244 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 614 ms 12224 KB Output is correct
2 Correct 599 ms 12140 KB Output is correct
3 Correct 611 ms 12164 KB Output is correct
4 Correct 612 ms 12224 KB Output is correct
5 Correct 601 ms 12204 KB Output is correct
6 Correct 606 ms 12168 KB Output is correct
7 Correct 613 ms 12208 KB Output is correct
8 Correct 628 ms 12180 KB Output is correct
9 Correct 617 ms 12216 KB Output is correct
10 Correct 620 ms 12176 KB Output is correct
11 Correct 618 ms 12220 KB Output is correct
12 Correct 615 ms 12260 KB Output is correct
13 Correct 607 ms 12240 KB Output is correct
14 Correct 606 ms 12148 KB Output is correct
15 Correct 634 ms 12200 KB Output is correct
16 Correct 108 ms 4372 KB Output is correct
17 Correct 117 ms 4588 KB Output is correct
18 Correct 109 ms 4532 KB Output is correct
19 Correct 124 ms 4512 KB Output is correct
20 Correct 111 ms 4424 KB Output is correct
21 Runtime error 6 ms 8660 KB Execution killed with signal 11
22 Halted 0 ms 0 KB -