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Submission #557301

# Submission time Handle Problem Language Result Execution time Memory
557301 2022-05-05T05:54:50 Z kwongweng Boat (APIO16_boat) C++17
36 / 100
 2000 ms 4616 KB 
/*
Solution for APIO 2016 - Boat
Tags : 
*/

#include <bits/stdc++.h>
using namespace std;
 
#pragma GCC target ("avx2")
#pragma GCC optimization ("Ofast")
#pragma GCC optimization ("unroll-loops")
 
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef long double ld;
typedef pair<ll, ll> pll;
#define FOR(i, a, b) for(int i = a; i < b; i++)
#define ROF(i, a, b) for(int i = a; i >= b; i--)
#define ms memset
#define pb push_back
#define fi first
#define se second
 
ll MOD = 1000000007;
 
ll power(ll base, ll n){
	if (n == 0) return 1;
	if (n == 1) return base;
	ll halfn = power(base, n/2);
	if (n % 2 == 0) return (halfn * halfn) % MOD;
	return (((halfn * halfn) % MOD) * base) % MOD;
}

vector<ll> inv(501,-1);
ll inverse(ll n){
    if (inv[n] != -1) return inv[n];
	return inv[n] = power(n, MOD-2);
}
 
ll add(ll a, ll b){
	return (a+b) % MOD;
}
 
ll mul(ll a, ll b){
	a %= MOD;
	return (a*b) % MOD;
}
 
ll gcd(ll a, ll b){
    if (a == 1) return 1;
    if (a == 0) return b;
    return gcd(b%a, a);
}

vector<ll> cnt[1000];
// cnt[i][j] = # solution for first ith school with last student sent is in ith compartment from left, and there are j students in the compartment

void solve(){
    int n; cin >> n;
    vector<ll> a(n), b(n); FOR(i,0,n) cin >> a[i] >> b[i];
    vector<pair<ll,int>> pos;
    FOR(i,0,n){
        b[i]++;
        pos.pb({a[i], i});
        pos.pb({b[i], i});
    }
    sort(pos.begin(), pos.end());
    vi l(n,-1), r(n,-1);
    FOR(i,0,2*n){
        int j = pos[i].se;
        if (l[j] == -1) l[j] = i;
        else r[j] = i;
    }
    FOR(i,0,2*n-1){
        cnt[i].pb(0);
    }
    FOR(i,0,n){
        ll total = 1;
        FOR(j,0,l[i]){
            for (ll val2 : cnt[j]){
                total += val2;
                total %= MOD;
            }
        }
        //compartment from l[i] to r[i]
        ll val[i+2];
        FOR(j,0,r[i]-l[i]){
            val[0] = 0;
            ll interval = pos[j+l[i]+1].fi - pos[j+l[i]].fi;
            val[1] = mul(interval,total);
            for (ll val2 : cnt[j+l[i]]){
                total += val2;
                total %= MOD;
            }
            FOR(k,2,i+2){
                ll new_val = 0;
                if (cnt[j+l[i]].size()>=k) new_val = cnt[j+l[i]][k-1];
                ll binom = mul(interval - k + 1, inverse(k)) ; // 
                new_val = mul(new_val, binom);
                val[k] = new_val;
            }
            FOR(k,1,i+2){
                if (k>=cnt[j+l[i]].size()){
                    cnt[j+l[i]].pb(val[k]);
                    continue;
                } 
                cnt[j+l[i]][k] = (cnt[j+l[i]][k] + val[k]) % MOD;
            }
        }
    }
    ll ans = 0;
    FOR(i,0,2*n-1){
        for (ll val2 : cnt[i]){
            ans = add(ans, val2);
        }
    }
    cout << ans;
}
 
int main() {
    ios::sync_with_stdio(false);
    if (fopen("input.txt", "r")) {
		freopen("input.txt", "r", stdin);
		freopen("output.txt", "w", stdout);
	}
    int TC = 1;
    //cin >> TC;
    FOR(i, 1, TC+1){
        //cout << "Case #" << i << ": ";
        solve();
    }
}

Compilation message

boat.cpp:10: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
   10 | #pragma GCC optimization ("Ofast")
      | 
boat.cpp:11: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
   11 | #pragma GCC optimization ("unroll-loops")
      | 
boat.cpp: In function 'void solve()':
boat.cpp:99:39: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   99 |                 if (cnt[j+l[i]].size()>=k) new_val = cnt[j+l[i]][k-1];
      |                     ~~~~~~~~~~~~~~~~~~^~~
boat.cpp:105:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  105 |                 if (k>=cnt[j+l[i]].size()){
      |                     ~^~~~~~~~~~~~~~~~~~~~
boat.cpp: In function 'int main()':
boat.cpp:125:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  125 |   freopen("input.txt", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
boat.cpp:126:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  126 |   freopen("output.txt", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 56 ms 1620 KB Output is correct
2 Correct 57 ms 1640 KB Output is correct
3 Correct 57 ms 1612 KB Output is correct
4 Correct 57 ms 1664 KB Output is correct
5 Correct 59 ms 1612 KB Output is correct
6 Correct 111 ms 1668 KB Output is correct
7 Correct 101 ms 1604 KB Output is correct
8 Correct 100 ms 1720 KB Output is correct
9 Correct 107 ms 1600 KB Output is correct
10 Correct 106 ms 1616 KB Output is correct
11 Correct 104 ms 1740 KB Output is correct
12 Correct 102 ms 1720 KB Output is correct
13 Correct 104 ms 1688 KB Output is correct
14 Correct 110 ms 1720 KB Output is correct
15 Correct 107 ms 1700 KB Output is correct
16 Correct 190 ms 3640 KB Output is correct
17 Correct 190 ms 3460 KB Output is correct
18 Correct 181 ms 3532 KB Output is correct
19 Correct 183 ms 3532 KB Output is correct
20 Correct 194 ms 3480 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 56 ms 1620 KB Output is correct
2 Correct 57 ms 1640 KB Output is correct
3 Correct 57 ms 1612 KB Output is correct
4 Correct 57 ms 1664 KB Output is correct
5 Correct 59 ms 1612 KB Output is correct
6 Correct 111 ms 1668 KB Output is correct
7 Correct 101 ms 1604 KB Output is correct
8 Correct 100 ms 1720 KB Output is correct
9 Correct 107 ms 1600 KB Output is correct
10 Correct 106 ms 1616 KB Output is correct
11 Correct 104 ms 1740 KB Output is correct
12 Correct 102 ms 1720 KB Output is correct
13 Correct 104 ms 1688 KB Output is correct
14 Correct 110 ms 1720 KB Output is correct
15 Correct 107 ms 1700 KB Output is correct
16 Correct 190 ms 3640 KB Output is correct
17 Correct 190 ms 3460 KB Output is correct
18 Correct 181 ms 3532 KB Output is correct
19 Correct 183 ms 3532 KB Output is correct
20 Correct 194 ms 3480 KB Output is correct
21 Correct 1556 ms 4536 KB Output is correct
22 Correct 1454 ms 4576 KB Output is correct
23 Correct 1418 ms 4572 KB Output is correct
24 Correct 1471 ms 4500 KB Output is correct
25 Correct 1416 ms 4616 KB Output is correct
26 Execution timed out 2012 ms 4008 KB Time limit exceeded
27 Halted 0 ms 0 KB -

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 468 KB Output is correct
2 Correct 12 ms 560 KB Output is correct
3 Correct 13 ms 468 KB Output is correct
4 Correct 14 ms 520 KB Output is correct
5 Correct 15 ms 692 KB Output is correct
6 Correct 19 ms 552 KB Output is correct
7 Correct 19 ms 568 KB Output is correct
8 Correct 20 ms 540 KB Output is correct
9 Correct 20 ms 572 KB Output is correct
10 Correct 20 ms 568 KB Output is correct
11 Correct 13 ms 556 KB Output is correct
12 Correct 11 ms 468 KB Output is correct
13 Correct 11 ms 552 KB Output is correct
14 Correct 11 ms 480 KB Output is correct
15 Correct 13 ms 564 KB Output is correct
16 Correct 13 ms 468 KB Output is correct
17 Correct 12 ms 572 KB Output is correct
18 Correct 13 ms 576 KB Output is correct
19 Correct 13 ms 556 KB Output is correct
20 Correct 14 ms 468 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 56 ms 1620 KB Output is correct
2 Correct 57 ms 1640 KB Output is correct
3 Correct 57 ms 1612 KB Output is correct
4 Correct 57 ms 1664 KB Output is correct
5 Correct 59 ms 1612 KB Output is correct
6 Correct 111 ms 1668 KB Output is correct
7 Correct 101 ms 1604 KB Output is correct
8 Correct 100 ms 1720 KB Output is correct
9 Correct 107 ms 1600 KB Output is correct
10 Correct 106 ms 1616 KB Output is correct
11 Correct 104 ms 1740 KB Output is correct
12 Correct 102 ms 1720 KB Output is correct
13 Correct 104 ms 1688 KB Output is correct
14 Correct 110 ms 1720 KB Output is correct
15 Correct 107 ms 1700 KB Output is correct
16 Correct 190 ms 3640 KB Output is correct
17 Correct 190 ms 3460 KB Output is correct
18 Correct 181 ms 3532 KB Output is correct
19 Correct 183 ms 3532 KB Output is correct
20 Correct 194 ms 3480 KB Output is correct
21 Correct 1556 ms 4536 KB Output is correct
22 Correct 1454 ms 4576 KB Output is correct
23 Correct 1418 ms 4572 KB Output is correct
24 Correct 1471 ms 4500 KB Output is correct
25 Correct 1416 ms 4616 KB Output is correct
26 Execution timed out 2012 ms 4008 KB Time limit exceeded
27 Halted 0 ms 0 KB -