제출 #554393

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
554393		fatemetmhr	Boat (APIO16_boat)	C++17	0 / 100	640 ms	7404 KiB

boat

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

#define all(x)     x.begin(), x.end()
#define fi         first
#define se         second
#define pb         push_back

const int maxn5 = 5e2 + 5;
const int maxnb = 1e3 + 10;
const int mod   = 1e9 + 7;

int ent[maxn5][maxn5], val[maxnb][maxn5];
int ent2[maxnb][maxn5], szb[maxnb];
int l[maxn5], r[maxn5], ansel[maxn5][maxnb];
int ansbl[maxnb];
vector <int> exx;

inline ll pw(ll a, ll b){
    ll ret = 1;
    for(; b; b >>= 1, a = a * a % mod)
        if(b&1) ret = ret * a % mod;
    return ret;
}

inline ll entof(ll n, ll r){
    ll s = 1, m = 1;
    for(int i = 0; i < r; i++){
        s = s * (n - i) % mod;
        m = m * (i + 1) % mod;
    }
    return (s * pw(m, mod - 2)) % mod;
}


int main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);


    int n; cin >> n;
    for(int i = 0; i < n; i++){
        cin >> l[i] >> r[i]; // (..]
        l[i]--;
        exx.pb(l[i]);
        exx.pb(r[i]);
    }
    sort(all(exx));
    exx.resize(unique(all(exx)) - exx.begin());
    for(int i = 0; i < n; i++){
        l[i] = lower_bound(all(exx), l[i]) - exx.begin() + 1;
        r[i] = lower_bound(all(exx), r[i]) - exx.begin() + 1;
        //cout << "segment " << i << ' ' << l[i] << ' ' << r[i] << endl;
    }
    for(int i = 1; i < exx.size(); i++)
        szb[i + 1] = exx[i] - exx[i - 1];
    int blsz = exx.size() + 2;

    ent[0][0] = 1;
    for(int i = 1; i < maxn5; i++){
        ent[i][0] = 1;
        for(int j = 1; j <= i; j++)
            ent[i][j] = (ent[i - 1][j - 1] + ent[i - 1][j]) % mod;
    }
    
    for(int i = 1; i < blsz; i++) for(int j = 0; j < maxn5 && j <= szb[i]; j++){
        ent2[i][j] = entof(szb[i], j);
    }


    for(int i = 1; i < blsz; i++) for(int j = 0; j < n; j++){ // bl e i om hast va j nafar davtalab
        // val[i][j] = SIGMA z : C(sz[i], z + 1) * C(j, z);
        for(int z = 0; z + 1 <= szb[i] && z <= j; z++)
            val[i][j] = (val[i][j] + ll(ent2[i][z + 1]) * ent[j][z]) % mod;
    }

    ansbl[0] = 1;
    for(int i = 0; i < n; i++){
        for(int j = l[i] + 1; j <= r[i]; j++){
            for(int k = 0; k < j; k++)
                ansel[i][j] = (ansel[i][j] + ansbl[k] * ll(szb[j])) % mod;
            if(i == 0)
                continue;
            int num = l[i - 1] < j && j <= r[i - 1];
            for(int k = i - 2; k >= 0; k--){
                //cout << "aha " << i << ' ' << j << ' ' << k << ' ' << num << ' ' << ansel[k][j - 1] << endl;
                if(num)
                    ansel[i][j] = (ansel[i][j] + ll(ansel[k][j - 1]) * val[j][num]) % mod;
                num += l[k] < j && j <= r[k];
            }
        }
        for(int j = l[i] + 1; j <= r[i]; j++){
            ansbl[j] = (ansbl[j] + ansel[i][j]) % mod;
            //cout << i << ' ' << j << ' ' << ansel[i][j] << endl;
        }
        for(int j = 1; j < blsz; j++)
            ansel[i][j] = (ansel[i][j - 1] + ansel[i][j]) % mod;
    }
    ll out = 0;
    for(int i = 1; i < blsz; i++)
        out += ansbl[i];
    cout << out % mod << endl;
}

컴파일 시 표준 에러 (stderr) 메시지

boat.cpp: In function 'int main()':
boat.cpp:57:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |     for(int i = 1; i < exx.size(); i++)
      |                    ~~^~~~~~~~~~~~

• Subtask 1: 0 / 9
• Subtask 2: 0 / 22
• Subtask 3: 0 / 27
• Subtask 4: 0 / 42