oj.uz

Submission #226189

# Submission time Handle Problem Language Result Execution time Memory
226189 2020-04-22T18:57:24 Z rqi Boat (APIO16_boat) C++14
9 / 100
 1614 ms 6520 KB 
#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef long double ld;
typedef double db; 
typedef string str; 

typedef pair<int,int> pi;
typedef pair<ll,ll> pl; 
typedef pair<db,db> pd; 

typedef vector<int> vi; 
typedef vector<ll> vl; 
typedef vector<db> vd; 
typedef vector<str> vs; 
typedef vector<pi> vpi;
typedef vector<pl> vpl; 
typedef vector<pd> vpd; 

#define mp make_pair 
#define f first
#define s second
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend() 
#define rsz resize
#define ins insert 
#define ft front() 
#define bk back()
#define pf push_front 
#define pb push_back
#define eb emplace_back 
#define lb lower_bound 
#define ub upper_bound 

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

const int MOD = 1e9+7; // 998244353;
const int MX = 2e5+5; 
const ll INF = 1e18; 
const ld PI = acos((ld)-1);
const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1}; 

template<class T> bool ckmin(T& a, const T& b) { 
    return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { 
    return a < b ? a = b, 1 : 0; } 
int pct(int x) { return __builtin_popcount(x); } 
int bit(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) 
int cdiv(int a, int b) { return a/b+!(a<0||a%b == 0); } // division of a by b rounded up, assumes b > 0 

// INPUT
template<class A> void re(complex<A>& c);
template<class A, class B> void re(pair<A,B>& p);
template<class A> void re(vector<A>& v);
template<class A, size_t SZ> void re(array<A,SZ>& a);

template<class T> void re(T& x) { cin >> x; }
void re(db& d) { str t; re(t); d = stod(t); }
void re(ld& d) { str t; re(t); d = stold(t); }
template<class H, class... T> void re(H& h, T&... t) { re(h); re(t...); }

template<class A> void re(complex<A>& c) { A a,b; re(a,b); c = {a,b}; }
template<class A, class B> void re(pair<A,B>& p) { re(p.f,p.s); }
template<class A> void re(vector<A>& x) { trav(a,x) re(a); }
template<class A, size_t SZ> void re(array<A,SZ>& x) { trav(a,x) re(a); }

// TO_STRING
#define ts to_string
template<class A, class B> str ts(pair<A,B> p);
template<class A> str ts(complex<A> c) { return ts(mp(c.real(),c.imag())); }
str ts(bool b) { return b ? "true" : "false"; }
str ts(char c) { str s = ""; s += c; return s; }
str ts(str s) { return s; }
str ts(const char* s) { return (str)s; }
str ts(vector<bool> v) { 
    bool fst = 1; str res = "{";
    F0R(i,sz(v)) {
        if (!fst) res += ", ";
        fst = 0; res += ts(v[i]);
    }
    res += "}"; return res;
}
template<size_t SZ> str ts(bitset<SZ> b) {
    str res = ""; F0R(i,SZ) res += char('0'+b[i]);
    return res; }
template<class T> str ts(T v) {
    bool fst = 1; str res = "{";
    for (const auto& x: v) {
        if (!fst) res += ", ";
        fst = 0; res += ts(x);
    }
    res += "}"; return res;
}
template<class A, class B> str ts(pair<A,B> p) {
    return "("+ts(p.f)+", "+ts(p.s)+")"; }

// OUTPUT
template<class A> void pr(A x) { cout << ts(x); }
template<class H, class... T> void pr(const H& h, const T&... t) { 
    pr(h); pr(t...); }
void ps() { pr("\n"); } // print w/ spaces
template<class H, class... T> void ps(const H& h, const T&... t) { 
    pr(h); if (sizeof...(t)) pr(" "); ps(t...); }

// DEBUG
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
    cerr << to_string(h); if (sizeof...(t)) cerr << ", ";
    DBG(t...); }
#ifdef LOCAL // compile with -DLOCAL
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 42
#endif

// FILE I/O
void setIn(string s) { freopen(s.c_str(),"r",stdin); }
void setOut(string s) { freopen(s.c_str(),"w",stdout); }
void unsyncIO() { ios_base::sync_with_stdio(0); cin.tie(0); }
void setIO(string s = "") {
    unsyncIO();
    // cin.exceptions(cin.failbit); 
    // throws exception when do smth illegal
    // ex. try to read letter into int
    if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
}

mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); 

/**
 * Description: modular arithmetic operations 
 * Source: 
    * KACTL
    * https://codeforces.com/blog/entry/63903
    * https://codeforces.com/contest/1261/submission/65632855 (tourist)
    * https://codeforces.com/contest/1264/submission/66344993 (ksun)
 * Verification: 
    * https://open.kattis.com/problems/modulararithmetic
 */

struct mi {
    typedef decay<decltype(MOD)>::type T; 
     /// don't silently convert to T
    T v; explicit operator T() const { return v; }
    mi() { v = 0; }
    mi(ll _v) { 
        v = (-MOD < _v && _v < MOD) ? _v : _v % MOD;
        if (v < 0) v += MOD;
    }
    friend bool operator==(const mi& a, const mi& b) { 
        return a.v == b.v; }
    friend bool operator!=(const mi& a, const mi& b) { 
        return !(a == b); }
    friend bool operator<(const mi& a, const mi& b) { 
        return a.v < b.v; }
    friend void re(mi& a) { ll x; re(x); a = mi(x); }
    friend str ts(mi a) { return ts(a.v); }
   
    mi& operator+=(const mi& m) { 
        if ((v += m.v) >= MOD) v -= MOD; 
        return *this; }
    mi& operator-=(const mi& m) { 
        if ((v -= m.v) < 0) v += MOD; 
        return *this; }
    mi& operator*=(const mi& m) { 
        v = (ll)v*m.v%MOD; return *this; }
    mi& operator/=(const mi& m) { return (*this) *= inv(m); }
    friend mi pow(mi a, ll p) {
        mi ans = 1; assert(p >= 0);
        for (; p; p /= 2, a *= a) if (p&1) ans *= a;
        return ans;
    }
    friend mi inv(const mi& a) { assert(a.v != 0); 
        return pow(a,MOD-2); }
        
    mi operator-() const { return mi(-v); }
    mi& operator++() { return *this += 1; }
    mi& operator--() { return *this -= 1; }
    friend mi operator+(mi a, const mi& b) { return a += b; }
    friend mi operator-(mi a, const mi& b) { return a -= b; }
    friend mi operator*(mi a, const mi& b) { return a *= b; }
    friend mi operator/(mi a, const mi& b) { return a /= b; }
};
typedef vector<mi> vmi;
typedef pair<mi,mi> pmi;
typedef vector<pmi> vpmi;

int N, M;
int a[505];
int b[505];
set<int> m;
map<int, int> ma;
int vals[1005];
mi dp1[1005];
mi dp2[1005][505];
mi ndp1[1005];
mi ndp2[1005][505];
mi comb[1005][505];

int main() {
    setIO();
    cin >> N;
    for(int i = 1; i <= N; i++){
        cin >> a[i] >> b[i];
        m.insert(a[i]);
        m.insert(b[i]);
    }

    M = sz(m);
    int cnt = 0;
    for(auto u: m){
        cnt++;
        vals[cnt] = u;
        ma[u] = cnt;
    }

    for(int i = 1; i <= N; i++){
        a[i] = ma[a[i]];
        b[i] = ma[b[i]];
    }

    for(int i = 1; i <= M-1; i++){
        int val = vals[i+1]-vals[i]-1;
        comb[i][0] = 1;
        for(int j = 1; j <= N; j++){
            comb[i][j] = comb[i][j-1]*mi(val-j+1)/mi(j);
        }
    }

    for(int i = 1; i <= N; i++){
        int l = a[i];
        int r = b[i];
        //calculate cdp values
        mi cdp[1005];
        cdp[1] = 1;
        for(int i = 2; i <= M; i++){
            cdp[i] = cdp[i-1]+dp1[i-1];
            for(int j = 1; j <= N; j++){
                cdp[i]+=dp2[i-1][j]*comb[i-1][j];
            }
        } 
        //calculate ndp1
        //calculate ndp2[1]
        for(int i = l; i <= r; i++){
            ndp1[i]+=cdp[i];
            if(i != r) ndp2[i][1]+=ndp1[i]+dp1[i];
        }
       
        //calculate ndp2[non1]
        for(int i = l; i <= r-1; i++){
            for(int j = 2; j <= N; j++){
                ndp2[i][j]+=ndp2[i][j-1];
            }
        }

        //add old dp values
        for(int i = 1; i <= M; i++){
            ndp1[i]+=dp1[i];
        }

        for(int i = 1; i <= M-1; i++){
             for(int j = 1; j <= N; j++){
                ndp2[i][j]+=dp2[i][j];
            }
        }


        //swap ndp, dp
        for(int i = 1; i <= M; i++){
            dp1[i] = ndp1[i];
            ndp1[i] = 0;
        }
        for(int i = 1; i <= M-1; i++){
            for(int j = 1; j <= N; j++){
                dp2[i][j] = ndp2[i][j];
                ndp2[i][j] = 0;
            }
        }
    }
    mi ans = 1;
    for(int i = 1; i <= M; i++){
        ans+=dp1[i];
    }
    for(int i = 1; i <= M-1; i++){
        for(int j = 1; j <= N; j++){
            ans+=dp2[i][j]*comb[i][j];
        }
    }
    //subtract empty case
    ps(ans-1);
    // you should actually read the stuff at the bottom
}

/* stuff you should look for
    * int overflow, array bounds
    * special cases (n=1?)
    * do smth instead of nothing and stay organized
    * WRITE STUFF DOWN
*/

Compilation message

boat.cpp: In function 'void setIn(std::__cxx11::string)':
boat.cpp:123:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setIn(string s) { freopen(s.c_str(),"r",stdin); }
                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
boat.cpp: In function 'void setOut(std::__cxx11::string)':
boat.cpp:124:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setOut(string s) { freopen(s.c_str(),"w",stdout); }
                         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 677 ms 6400 KB Output is correct
2 Correct 673 ms 6520 KB Output is correct
3 Correct 674 ms 6520 KB Output is correct
4 Correct 675 ms 6400 KB Output is correct
5 Correct 677 ms 6420 KB Output is correct
6 Correct 677 ms 6520 KB Output is correct
7 Correct 683 ms 6424 KB Output is correct
8 Correct 673 ms 6456 KB Output is correct
9 Correct 680 ms 6520 KB Output is correct
10 Correct 678 ms 6520 KB Output is correct
11 Correct 687 ms 6520 KB Output is correct
12 Correct 691 ms 6520 KB Output is correct
13 Correct 682 ms 6520 KB Output is correct
14 Correct 690 ms 6520 KB Output is correct
15 Correct 688 ms 6400 KB Output is correct
16 Correct 126 ms 6272 KB Output is correct
17 Correct 143 ms 6272 KB Output is correct
18 Correct 131 ms 6272 KB Output is correct
19 Correct 138 ms 6272 KB Output is correct
20 Correct 132 ms 6392 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 677 ms 6400 KB Output is correct
2 Correct 673 ms 6520 KB Output is correct
3 Correct 674 ms 6520 KB Output is correct
4 Correct 675 ms 6400 KB Output is correct
5 Correct 677 ms 6420 KB Output is correct
6 Correct 677 ms 6520 KB Output is correct
7 Correct 683 ms 6424 KB Output is correct
8 Correct 673 ms 6456 KB Output is correct
9 Correct 680 ms 6520 KB Output is correct
10 Correct 678 ms 6520 KB Output is correct
11 Correct 687 ms 6520 KB Output is correct
12 Correct 691 ms 6520 KB Output is correct
13 Correct 682 ms 6520 KB Output is correct
14 Correct 690 ms 6520 KB Output is correct
15 Correct 688 ms 6400 KB Output is correct
16 Correct 126 ms 6272 KB Output is correct
17 Correct 143 ms 6272 KB Output is correct
18 Correct 131 ms 6272 KB Output is correct
19 Correct 138 ms 6272 KB Output is correct
20 Correct 132 ms 6392 KB Output is correct
21 Incorrect 1614 ms 6400 KB Output isn't correct
22 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 25 ms 6272 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 677 ms 6400 KB Output is correct
2 Correct 673 ms 6520 KB Output is correct
3 Correct 674 ms 6520 KB Output is correct
4 Correct 675 ms 6400 KB Output is correct
5 Correct 677 ms 6420 KB Output is correct
6 Correct 677 ms 6520 KB Output is correct
7 Correct 683 ms 6424 KB Output is correct
8 Correct 673 ms 6456 KB Output is correct
9 Correct 680 ms 6520 KB Output is correct
10 Correct 678 ms 6520 KB Output is correct
11 Correct 687 ms 6520 KB Output is correct
12 Correct 691 ms 6520 KB Output is correct
13 Correct 682 ms 6520 KB Output is correct
14 Correct 690 ms 6520 KB Output is correct
15 Correct 688 ms 6400 KB Output is correct
16 Correct 126 ms 6272 KB Output is correct
17 Correct 143 ms 6272 KB Output is correct
18 Correct 131 ms 6272 KB Output is correct
19 Correct 138 ms 6272 KB Output is correct
20 Correct 132 ms 6392 KB Output is correct
21 Incorrect 1614 ms 6400 KB Output isn't correct
22 Halted 0 ms 0 KB -