Submission #134496

#	Time	Username	Problem	Language	Result	Execution time	Memory
134496		Benq	Cultivation (JOI17_cultivation)	C++14	100 / 100	1849 ms	13408 KiB

cultivation

#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>

using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

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

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define F0R(i, a) for (int i = 0; i < (a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= (a); i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)
#define trav(a, x) for (auto& a : x)

#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound

#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rsz resize

const int MOD = 1000000007; // 998244353
const ll INF = 1e18;
const int MX = 200005;
const ld PI = 4*atan((ld)1);

template<class T> void ckmin(T &a, T b) { a = min(a, b); }
template<class T> void ckmax(T &a, T b) { a = max(a, b); }

namespace input {
    template<class T> void re(complex<T>& x);
    template<class T1, class T2> void re(pair<T1,T2>& p);
    template<class T> void re(vector<T>& a);
    template<class T, size_t SZ> void re(array<T,SZ>& a);

    template<class T> void re(T& x) { cin >> x; }
    void re(double& x) { string t; re(t); x = stod(t); }
    void re(ld& x) { string t; re(t); x = stold(t); }
    template<class Arg, class... Args> void re(Arg& first, Args&... rest) { 
        re(first); re(rest...); 
    }

    template<class T> void re(complex<T>& x) { T a,b; re(a,b); x = cd(a,b); }
    template<class T1, class T2> void re(pair<T1,T2>& p) { re(p.f,p.s); }
    template<class T> void re(vector<T>& a) { F0R(i,sz(a)) re(a[i]); }
    template<class T, size_t SZ> void re(array<T,SZ>& a) { F0R(i,SZ) re(a[i]); }
}

using namespace input;

namespace output {
    template<class T1, class T2> void pr(const pair<T1,T2>& x);
    template<class T, size_t SZ> void pr(const array<T,SZ>& x);
    template<class T> void pr(const vector<T>& x);
    template<class T> void pr(const set<T>& x);
    template<class T1, class T2> void pr(const map<T1,T2>& x);

    template<class T> void pr(const T& x) { cout << x; }
    template<class Arg, class... Args> void pr(const Arg& first, const Args&... rest) { 
        pr(first); pr(rest...); 
    }

    template<class T1, class T2> void pr(const pair<T1,T2>& x) { 
        pr("{",x.f,", ",x.s,"}"); 
    }
    template<class T> void prContain(const T& x) {
        pr("{");
        bool fst = 1; for (const auto& a: x) pr(!fst?", ":"",a), fst = 0; // const needed for vector<bool>
        pr("}");
    }
    template<class T, size_t SZ> void pr(const array<T,SZ>& x) { prContain(x); }
    template<class T> void pr(const vector<T>& x) { prContain(x); }
    template<class T> void pr(const set<T>& x) { prContain(x); }
    template<class T1, class T2> void pr(const map<T1,T2>& x) { prContain(x); }
    
    void ps() { pr("\n"); }
    template<class Arg> void ps(const Arg& first) { 
        pr(first); ps(); // no space at end of line
    }
    template<class Arg, class... Args> void ps(const Arg& first, const Args&... rest) { 
        pr(first," "); ps(rest...); // print w/ spaces
    }
}

using namespace output;

namespace io {
    void setIn(string s) { freopen(s.c_str(),"r",stdin); }
    void setOut(string s) { freopen(s.c_str(),"w",stdout); }
    void setIO(string s = "") {
        ios_base::sync_with_stdio(0); cin.tie(0); // fast I/O
        if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
    }
}

using namespace io;

template<class T> T invGeneral(T a, T b) {
    a %= b; if (a == 0) return b == 1 ? 0 : -1;
    T x = invGeneral(b,a); 
    return x == -1 ? -1 : ((1-(ll)b*x)/a+b)%b;
}

template<class T> struct modular {
    T val; 
    explicit operator T() const { return val; }
    modular() { val = 0; }
    modular(const ll& v) { 
        val = (-MOD <= v && v <= MOD) ? v : v % MOD;
        if (val < 0) val += MOD;
    }
    
    friend ostream& operator<<(ostream& os, const modular& a) { return os << a.val; }
    friend bool operator==(const modular& a, const modular& b) { return a.val == b.val; }
    friend bool operator!=(const modular& a, const modular& b) { return !(a == b); }
    friend bool operator<(const modular& a, const modular& b) { return a.val < b.val; }

    modular operator-() const { return modular(-val); }
    modular& operator+=(const modular& m) { if ((val += m.val) >= MOD) val -= MOD; return *this; }
    modular& operator-=(const modular& m) { if ((val -= m.val) < 0) val += MOD; return *this; }
    modular& operator*=(const modular& m) { val = (ll)val*m.val%MOD; return *this; }
    friend modular pow(modular a, ll p) {
        modular ans = 1; for (; p; p /= 2, a *= a) if (p&1) ans *= a;
        return ans;
    }
    friend modular inv(const modular& a) { 
        auto i = invGeneral(a.val,MOD); assert(i != -1);
        return i;
    } // equivalent to return exp(b,MOD-2) if MOD is prime
    modular& operator/=(const modular& m) { return (*this) *= inv(m); }
    
    friend modular operator+(modular a, const modular& b) { return a += b; }
    friend modular operator-(modular a, const modular& b) { return a -= b; }
    friend modular operator*(modular a, const modular& b) { return a *= b; }
    
    friend modular operator/(modular a, const modular& b) { return a /= b; }
};

typedef modular<int> mi;
typedef pair<mi,mi> pmi;
typedef vector<mi> vmi;
typedef vector<pmi> vpmi;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
 
int R,C,N;
ll ans = INF;
vpl p;
vl totest;

struct con {
	multiset<int> cur, cdif;
	array<int,3> ans = {MOD,MOD,MOD};
	
	array<int,3> ret() {
	    if (!sz(cur)) return {MOD,MOD,MOD};
	    int dif = sz(cdif)?*cdif.rbegin():0;
	    dif = max(dif,max(*cur.begin(),C-1-*cur.rbegin()));
	    return {*cur.begin(),C-1-*cur.rbegin(),dif};
	}
 
	void process(int x) {
		auto it = cur.insert(x);
        if (it != cur.begin() && next(it) != cur.end()) cdif.erase(cdif.find(*next(it)-*prev(it)-1));
        if (it != cur.begin()) cdif.insert(*it-*prev(it)-1);
        if (next(it) != cur.end()) cdif.insert(*next(it)-*it-1);
        ans = ret();
	}
};
 
con c[300][2];
int l[300][2], r[300][2];
 
// p[i].f: find all j such that p[j].f <= p[i].f && p[j].f+r >= p[i].f 
// p[i].f+r+1: find all j such that p[j].f > p[i].f && p[j].f <= p[i].f+r+1

vector<array<ll,4>> todo;

void init() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> R >> C >> N; p.resize(N);
    F0R(i,N) {
        cin >> p[i].f >> p[i].s;
        p[i].f --, p[i].s --;
    }
    sort(all(p));
    F0R(i,N) F0R(j,N) totest.pb(p[i].f+R-1-p[j].f);
    F0R(i,N) F0R(j,N) totest.pb(max(p[i].f-p[j].f-1,0LL));
    sort(all(totest)); totest.erase(unique(all(totest)),totest.end());
    F0R(i,N) {
    	F0R(j,N) {
    		if (p[j].f <= p[i].f) todo.pb({p[i].f-p[j].f,p[j].s,i,0});
    		else todo.pb({p[j].f-p[i].f-1,p[j].s,i,1});
    	}
    }
    sort(all(todo)); reverse(all(todo));
}
 
struct MaxDeque {
	pi d[600];
	int l, r;
    void ad(int ind, int val) {
        while (r >= l && d[r].f <= val) r --;
        d[++r] = {val,ind};
    }
    void rem(int ind) {
        if (d[l].s == ind) l ++;
    }
    int get() { return d[l].f; }
};

void upd(int r) {
	while (sz(todo) && todo.back()[0] <= r) {
		c[todo.back()[2]][todo.back()[3]].process(todo.back()[1]);
		todo.pop_back();
	}
}

pair<int,array<int,3>> dat[600];
MaxDeque D[3]; 

void tri(int r) {
    upd(r);
    int sz = 0;
    int i0 = 0, i1 = 0;
    while (i1 < N) {
    	if (i0 != N && p[i0].f <= p[i1].f+r+1) {
    		if (!sz || dat[sz-1].f != p[i0].f)
    			dat[sz++] = {p[i0].f,c[i0][0].ans};
        	i0 ++;
    	} else {
    		if (!sz || dat[sz-1].f != p[i1].f+r+1) 
    			dat[sz++] = {p[i1].f+r+1,c[i1][1].ans};
        	i1 ++;
    	} 
    }
    F0R(i,3) D[i].l = 0, D[i].r = -1;
    int nex = 0;
    F0R(i,sz) if (dat[i].f <= r) {
        while (nex < sz && dat[nex].f < dat[i].f+R) {
            F0R(j,3) D[j].ad(nex,dat[nex].s[j]);
            nex ++;
        }
        if (D[0].get() < MOD) ans = min(ans,(ll)r+max(D[0].get()+D[1].get(),D[2].get()));
        F0R(j,3) D[j].rem(i);
    } else break;
}
 
int main() {
    init();
    clock_t ori = clock();
    for (int i: totest) {
    	if ((double)(clock()-ori) > 1.8*CLOCKS_PER_SEC) break;
    	tri(i);
    }
    cout << ans;
}
 
/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( ) 
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/

Compilation message (stderr)

cultivation.cpp: In function 'void io::setIn(std::__cxx11::string)':
cultivation.cpp:113:35: 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); }
                            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
cultivation.cpp: In function 'void io::setOut(std::__cxx11::string)':
cultivation.cpp:114:36: 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: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 30 / 30
• Subtask 5: 20 / 20
• Subtask 6: 20 / 20