oj.uz

Submission #825632

# Submission time Handle Problem Language Result Execution time Memory
825632 2023-08-15T06:42:51 Z GrindMachine Boat (APIO16_boat) C++17
9 / 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;
        }
    }

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

    rep1(i,n){
        auto [l,r] = a[i];
        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;
            auto [lx,rx] = ranges[j];
            if(max(l,lx) <= min(r,rx)){
                dp[i][j] += dp[i-1][j-1];
                dp[i][j] %= MOD;

                rev(k,i-1,1){
                    // i and k fixed
                    // few more in between
                    ll len = i-k+1;
                    rep(more,len-2+1){
                        ll choose_guys = ncr(len-2,more);
                        ll choose_points = choose[j][more+2];
                        dp[i][j] += choose_guys*choose_points;
                        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 109 ms 8276 KB Output is correct
2 Correct 108 ms 8312 KB Output is correct
3 Correct 108 ms 8308 KB Output is correct
4 Correct 112 ms 8304 KB Output is correct
5 Correct 109 ms 8308 KB Output is correct
6 Correct 109 ms 8328 KB Output is correct
7 Correct 108 ms 8276 KB Output is correct
8 Correct 111 ms 8304 KB Output is correct
9 Correct 115 ms 8308 KB Output is correct
10 Correct 112 ms 8308 KB Output is correct
11 Correct 109 ms 8308 KB Output is correct
12 Correct 109 ms 8308 KB Output is correct
13 Correct 108 ms 8312 KB Output is correct
14 Correct 110 ms 8312 KB Output is correct
15 Correct 116 ms 8308 KB Output is correct
16 Correct 102 ms 1748 KB Output is correct
17 Correct 103 ms 1876 KB Output is correct
18 Correct 102 ms 1748 KB Output is correct
19 Correct 102 ms 1876 KB Output is correct
20 Correct 105 ms 1832 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 109 ms 8276 KB Output is correct
2 Correct 108 ms 8312 KB Output is correct
3 Correct 108 ms 8308 KB Output is correct
4 Correct 112 ms 8304 KB Output is correct
5 Correct 109 ms 8308 KB Output is correct
6 Correct 109 ms 8328 KB Output is correct
7 Correct 108 ms 8276 KB Output is correct
8 Correct 111 ms 8304 KB Output is correct
9 Correct 115 ms 8308 KB Output is correct
10 Correct 112 ms 8308 KB Output is correct
11 Correct 109 ms 8308 KB Output is correct
12 Correct 109 ms 8308 KB Output is correct
13 Correct 108 ms 8312 KB Output is correct
14 Correct 110 ms 8312 KB Output is correct
15 Correct 116 ms 8308 KB Output is correct
16 Correct 102 ms 1748 KB Output is correct
17 Correct 103 ms 1876 KB Output is correct
18 Correct 102 ms 1748 KB Output is correct
19 Correct 102 ms 1876 KB Output is correct
20 Correct 105 ms 1832 KB Output is correct
21 Execution timed out 2072 ms 13524 KB Time limit exceeded
22 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 102 ms 984 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 109 ms 8276 KB Output is correct
2 Correct 108 ms 8312 KB Output is correct
3 Correct 108 ms 8308 KB Output is correct
4 Correct 112 ms 8304 KB Output is correct
5 Correct 109 ms 8308 KB Output is correct
6 Correct 109 ms 8328 KB Output is correct
7 Correct 108 ms 8276 KB Output is correct
8 Correct 111 ms 8304 KB Output is correct
9 Correct 115 ms 8308 KB Output is correct
10 Correct 112 ms 8308 KB Output is correct
11 Correct 109 ms 8308 KB Output is correct
12 Correct 109 ms 8308 KB Output is correct
13 Correct 108 ms 8312 KB Output is correct
14 Correct 110 ms 8312 KB Output is correct
15 Correct 116 ms 8308 KB Output is correct
16 Correct 102 ms 1748 KB Output is correct
17 Correct 103 ms 1876 KB Output is correct
18 Correct 102 ms 1748 KB Output is correct
19 Correct 102 ms 1876 KB Output is correct
20 Correct 105 ms 1832 KB Output is correct
21 Execution timed out 2072 ms 13524 KB Time limit exceeded
22 Halted 0 ms 0 KB -