Submission #366168

#	Time	Username	Problem	Language	Result	Execution time	Memory
366168		ACmachine	Bulldozer (JOI17_bulldozer)	C++17	100 / 100	1573 ms	50104 KiB

bulldozer

#include <bits/stdc++.h>
using namespace std;

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T, typename U> using ordered_map = tree<T, U, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long ll;
typedef long double ld;
typedef double db;
typedef string str;

typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<str> vstr;

#define FOR(i,j,k,in) for(int i=(j); i < (k);i+=in)
#define FORD(i,j,k,in) for(int i=(j); i >=(k);i-=in)
#define REP(i,b) FOR(i,0,b,1)
#define REPD(i,b) FORD(i,b,0,1)
#define pb push_back 
#define mp make_pair
#define ff first
#define ss second
#define all(x) begin(x), end(x)
#define rsz resize 
#define MANY_TESTS int tcase; cin >> tcase; while(tcase--)
	
const double EPS = 1e-9;
const int MOD = 1e9+7; // 998244353;
const ll INFF = 1e18;
const int INF = 1e9;
const ld PI = acos((ld)-1);
const vi dy = {1, 0, -1, 0, -1, 1, 1, -1};
const vi dx = {0, 1, 0, -1, -1, 1, -1, 1};

#ifdef DEBUG
#define DBG if(1)
#else
#define DBG if(0)
#endif

#define dbg(x) cout << "(" << #x << " : " << x << ")" << endl;
// ostreams
template <class T, class U>
ostream& operator<<(ostream& out, const pair<T, U> &par) {out << "[" << par.first << ";" << par.second << "]"; return out;}
template <class T>
ostream& operator<<(ostream& out, const set<T> &cont) { out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template <class T, class U>
ostream& operator<<(ostream& out, const map<T, U> &cont) {out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template<class T>
ostream& operator<<(ostream& out, const vector<T> &v){ out << "[";  REP(i, v.size()) out << v[i] << ", ";  out << "]"; return out;}
// istreams
template<class T>
istream& operator>>(istream& in, vector<T> &v){ for(auto &x : v) in >> x; return in; }
template<class T, class U>
istream& operator>>(istream& in, pair<T, U> &p){ in >> p.ff >> p.ss; return in; }
//searches
template<typename T, typename U>
T bsl(T lo, T hi, U f){ hi++; T mid; while(lo < hi){ mid = (lo + hi)/2; f(mid) ? hi = mid : lo = mid+1; } return lo; }
template<typename U>
double bsld(double lo, double hi, U f, double p = 1e-9){ int r = 3 + (int)log2((hi - lo)/p); double mid; while(r--){ mid = (lo + hi)/2; f(mid) ? hi = mid : lo = mid; } return (lo + hi)/2; }
template<typename T, typename U>
T bsh(T lo, T hi, U f){ lo--; T mid; while(lo < hi){ mid = (lo + hi + 1)/2; f(mid) ? lo = mid : hi = mid-1; } return lo; }
template<typename U>
double bshd(double lo, double hi, U f, double p = 1e-9){ int r = 3+(int)log2((hi - lo)/p); double mid; while(r--){ mid = (lo + hi)/2; f(mid) ? lo = mid : hi = mid; } return (lo + hi)/2; }
// some more utility functions
template<typename T>
pair<T, int> get_min(vector<T> &v){ typename vector<T> :: iterator it = min_element(v.begin(), v.end()); return mp(*it, it - v.begin());}
template<typename T>
pair<T, int> get_max(vector<T> &v){ typename vector<T> :: iterator it = max_element(v.begin(), v.end()); return mp(*it, it - v.begin());}        
template<typename T> bool ckmin(T& a, const T& b){return b < a ? a = b , true : false;}
template<typename T> bool ckmax(T& a, const T& b){return b > a ? a = b, true : false;}

struct node{
    ll whole = 0, pref = 0, suf = 0;
    ll ans = 0;
    void apply(int l, int r, ll val){
        whole = val;
        pref = max(0ll, val);
        suf = max(0ll, val);
        ans = max(0ll, val);
    }
};
struct segtree{
    node comb(node const &a, node const &b){
        node res;
        res.whole = a.whole + b.whole;
        res.ans = max(a.ans, b.ans);
        res.ans = max(res.ans, a.suf + b.pref);
        res.pref = max(a.pref, a.whole + b.pref);
        res.suf = max(b.suf, b.whole + a.suf);
        return res;
    } 
    void push(int l, int r, int v){
        /* tree[v<<1].lazy += tree[v].lazy; */
        /* tree[v<<1|1].lazy += tree[v].lazy; */
        /* int mid = (l + r) >> 1; */
        /* tree[v<<1].ans += (mid - l) * tree[v].lazy; */
        /* tree[v<<1|1].ans += (r - mid)* tree[v].lazy; */
        /* tree[v].lazy = 0; */
    }
    int sz;
    vector<node> tree; 
    segtree(int _sz){ // tree is resized to default values set in node
        sz = 1; while(sz < _sz) sz<<=1;
        tree.resize(2*sz); 
    } 
    void build(vector<node> &init){
        for(int i = 0; i < sz; ++i) 
            if(i < init.size())
                tree[i+sz] = init[i];
        for(int i = sz-1; i > 0; --i)
            tree[i] = comb(tree[i<<1], tree[i<<1|1]);
    } 
    node query(int l, int r){return query0(l, r, 0, sz, 1);} 
    node query0(int l, int r, int beg, int end, int v){ 
        if(beg >= l && end <= r)
            return tree[v];
        push(beg, end, v);
        int mid = (beg + end) >> 1;
        node res;
        if(beg >= r || mid <= l) res = query0(l, r, mid, end, v<<1|1); //[beg, mid]
        else if(mid >= r || end <= l) res = query0(l, r, beg, mid, v<<1);
        else res = comb(query0(l, r, beg, mid, v<<1), query0(l, r, mid, end, v<<1|1));
        return res;
    } 
    template<typename... T>
    void upd(int l, int r, T ...args){upd0(l, r, 0, sz, 1, args...);}
    template<typename... T>
    void upd0(int l, int r, int beg, int end, int v, T ...args){
        if(beg >= r || end <= l)
            return;
        if(beg >= l && end <= r){
            tree[v].apply(beg, end, args...);
            return;
        }
        push(beg, end, v);
        int mid = (beg + end) >> 1;
        upd0(l, r, beg, mid, v<<1, args...);
        upd0(l, r, mid, end, v<<1|1, args...);
        tree[v] = comb(tree[v<<1], tree[v<<1|1]);
    } 
};

    
struct Frac{
    long long n, d;
    Frac(long long n, long long d){
        if(d == 0){
            this->d = 0;
            this->n = 1;
            return;
        } 
        this->n = n; this->d = d;
        long long g = __gcd(n, d); this->n/=g;  this->d/=g;
        if(this->d < 0){ this->n*=-1; this->d*=-1; };
    }
    Frac(long long n){
        this->n = n; d = 1;
    }
    Frac(){n = 0; d = 1;}
    
    Frac operator-(){return Frac(-n, d);}
    Frac operator+=(const Frac& other){return Frac(n*other.d + other.n*d, d*other.d);}
    Frac operator-=(const Frac& other){return Frac(n*other.d - other.n*d, d*other.d);}
    Frac operator*=(const Frac& other){return Frac(n*other.n, d*other.d);}
    Frac operator/=(const Frac& other){return Frac(n*other.d, d*other.n);}

    friend Frac operator+(Frac a, const Frac& b){ return a+=b; }
    friend Frac operator-(Frac a, const Frac& b){ return a-=b; }
    friend Frac operator*(Frac a, const Frac& b){ return a*=b; }
    friend Frac operator/(Frac a, const Frac& b){ return a/=b; }

    bool operator==(const Frac& other){ return n==other.n && d==other.d; }
    bool operator<(const Frac& other){ return n*other.d < other.n*d; }
    bool operator!=(const Frac& other){ return !((*this)==other);}
    
    friend string ts(const Frac& a){ return to_string(a.n) + "/" + to_string(a.d); }
    friend ostream& operator<<(ostream& out, Frac &a) { return out << ts(a); } 
};

int main(){
 	ios_base::sync_with_stdio(false);
 	cin.tie(NULL); cout.tie(NULL);
	int n; cin >> n;
    vector<array<ll, 3>> points(n);
    REP(i, n){
        cin >> points[i][0] >> points[i][1] >> points[i][2];
    }
    sort(all(points));
    vector<pair<Frac, array<int, 2>>> slope_changing_points;
    REP(i, n){
        REP(j, i){
            if(points[i][0] == points[j][0]) continue; 
            Frac slope = Frac(points[i][1] - points[j][1], points[i][0] - points[j][0]);
            array<int, 2> p = {j, i};
            slope_changing_points.pb(mp(slope, p));
        }
    }   
    sort(all(slope_changing_points), [](pair<Frac, array<int, 2>> lhs, pair<Frac, array<int, 2>> rhs){
        return tie(lhs.ff, lhs.ss[0], lhs.ss[1]) < tie(rhs.ff, rhs.ss[0], rhs.ss[1]);
    });
    vi pos(n); REP(i, n) pos[i] = i;
    vector<node> init(n);
    REP(i, n) init[i].apply(0, 0, points[i][2]);
    segtree st(n); st.build(init);
    ll ans = st.query(0, n).ans;
    REP(i, slope_changing_points.size()){
        auto &vect = slope_changing_points[i].ss;
        swap(pos[vect[0]], pos[vect[1]]); 
        REP(j, 2) st.upd(pos[vect[j]], pos[vect[j]] + 1, points[vect[j]][2]);
        if(i == (int)slope_changing_points.size() - 1 || slope_changing_points[i].ff != slope_changing_points[i + 1].ff)
            ans = max(ans, st.query(0, n).ans); 
    }
    cout << ans << "\n";	
    return 0;
}

Compilation message (stderr)

bulldozer.cpp: In member function 'void segtree::build(std::vector<node>&)':
bulldozer.cpp:120:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<node>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  120 |             if(i < init.size())
      |                ~~^~~~~~~~~~~~~
bulldozer.cpp: In function 'int main()':
bulldozer.cpp:26:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<Frac, std::array<int, 2> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 | #define FOR(i,j,k,in) for(int i=(j); i < (k);i+=in)
      |                                        ^
bulldozer.cpp:28:18: note: in expansion of macro 'FOR'
   28 | #define REP(i,b) FOR(i,0,b,1)
      |                  ^~~
bulldozer.cpp:218:5: note: in expansion of macro 'REP'
  218 |     REP(i, slope_changing_points.size()){
      |     ^~~

• Subtask 1: 5 / 5
• Subtask 2: 20 / 20
• Subtask 3: 35 / 35
• Subtask 4: 20 / 20
• Subtask 5: 20 / 20