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Submission #60397

# Submission time Handle Problem Language Result Execution time Memory
60397 2018-07-24T05:17:45 Z Benq Bulldozer (JOI17_bulldozer) C++14
5 / 100
 12 ms 1180 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;
 
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 sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()

const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 2000;

int ad(int a, int b) { return a+b; }
int sub(int a, int b) { return a-b; }

pi operator+(const pi& l, const pi& r) { return {ad(l.f,r.f),ad(l.s,r.s)}; }
pi operator-(const pi& l, const pi& r) { return {sub(l.f,r.f),sub(l.s,r.s)}; }
pi operator+=(pi& l, const pi& r) { return l = l+r; }
pi operator-=(pi& l, const pi& r) { return l = l-r; }

int N;
pair<pi,int> A[MX];
bool done[MX][MX];
vector<pair<pi,vi>> al;
ll ans = 0;

struct node {
    ll sum,mn,mx,ans;
    node(int w) {
        sum = w;
        mn = min(0,w);
        mx = ans = max(0,w);
    }
    node(): node(0) {}
};

node comb(const node& l, const node& r) {
    node res(0);
    res.ans = max(max(l.ans,r.ans),l.sum+r.mx-l.mn);
    res.mn = min(l.sum+r.mn,l.mn);
    res.mx = max(l.sum+r.mx,l.mx);
    res.sum = l.sum+r.sum;
    return res;
};

struct Seg {
    int ind[2000], rind[2000];
    node seg[4096];
    
    void init() {
        F0R(i,N) {
            rind[i] = ind[i] = i;
            seg[i^(1<<11)] = node(A[i].s);
        }
        FORd(i,1,11) seg[i] = comb(seg[2*i],seg[2*i+1]);
    }
    
    void upd(int ind) {
        ind ^= (1<<11);
        for (ind /= 2; ind; ind /= 2) seg[ind] = comb(seg[2*ind],seg[2*ind+1]);
    }
    
    void flip(vi v) {
        int mn = MOD, mx = -MOD;
        for (int i: v) mn = min(mn,ind[i]), mx = max(mx,ind[i]);
        assert(mx-mn+1 == sz(v));
        
        for (int i = mn; i < mx+mn-i; ++i) {
            swap(seg[i^(1<<11)],seg[(mx+mn-i)^(1<<11)]);
            swap(rind[i],rind[mx+mn-i]);
            swap(ind[rind[i]],ind[rind[mx+mn-i]]);
            upd(i);
            upd(mx+mn-i);
        }
    }
};

Seg S;

void ins(vi v) {
    F0R(i,sz(v)) FOR(j,i+1,sz(v)) done[v[i]][v[j]] = done[v[j]][v[i]] = 1;
    al.pb({A[v[1]].f-A[v[0]].f,v});
}

ll cross(pi b, pi c) {
    return (ll)b.f*c.s-(ll)b.s*c.f;
}

ll cross(pi a, pi b, pi c) { return cross(b-a,c-a); }

bool cmp(pi a, pi b) { return cross(a,b) > 0; }

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> N;
    F0R(i,N) cin >> A[i].f.f >> A[i].f.s >> A[i].s;
    if (N == 1) {
        cout << max(0,A[0].s);
        exit(0);
    }
    
    sort(A,A+N,[](pair<pi,int> x, pair<pi,int> y) {
        if (x.f.s != y.f.s) return x.f.s < y.f.s;
        return x.f.f < y.f.f;
    });
    S.init();
    
    /*F0R(i,N) cout << A[i].f.f << " " << A[i].f.s << "\n";
    cout << "\n";*/
    F0R(i,N) {
        vi v; FOR(j,i+1,N) v.pb(j);
        sort(all(v),[&i](int a, int b) { return cmp(A[a].f-A[i].f,A[b].f-A[i].f); });
        for (int ind = 0; ind < sz(v); ) {
            if (done[i][v[ind]]) {
                ind ++;
                continue;
            }
            int IND = ind;
            vi tmp = {i};
            while (ind < sz(v) && cross(A[i].f,A[v[IND]].f,A[v[ind]].f) == 0) tmp.pb(v[ind++]);
            // cout << "OOPS " << IND << " " << ind << "\n";
            // cout << A[i].f << " " << A[IND].f << " " << A[ind].f << "\n";
            ins(tmp);
        }
        /*cout << A[i].f.f << " " << A[i].f.s << "\n";
        for (auto x: v) cout << A[x].f.f << " " << A[x].f.s << " | ";
        cout << "\n";*/
    }
    sort(all(al), [](pair<pi,vi> a, pair<pi,vi> b) { return cmp(a.f,b.f); });
    /*for (auto a: al) {
        cout << a.f.f << " " << a.f.s << " | ";
        for (int i: a.s) cout << i << " ";
        cout << "\n";
    }*/
    for (int i = 0; i < sz(al); ) {
        int I = i;
        while (i < sz(al) && cross(al[I].f,al[i].f) == 0) S.flip(al[i++].s);
        ans = max(ans,S.seg[1].ans);
    }
    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
*/

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 640 KB Output is correct
2 Correct 2 ms 768 KB Output is correct
3 Correct 2 ms 640 KB Output is correct
4 Correct 3 ms 768 KB Output is correct
5 Correct 2 ms 640 KB Output is correct
6 Correct 2 ms 768 KB Output is correct
7 Correct 2 ms 768 KB Output is correct
8 Correct 2 ms 688 KB Output is correct
9 Correct 2 ms 640 KB Output is correct
10 Correct 2 ms 640 KB Output is correct
11 Correct 2 ms 512 KB Output is correct
12 Correct 2 ms 512 KB Output is correct
13 Correct 2 ms 512 KB Output is correct
14 Correct 2 ms 512 KB Output is correct
15 Correct 2 ms 512 KB Output is correct

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 1024 KB Output is correct
2 Correct 12 ms 1180 KB Output is correct
3 Incorrect 11 ms 1152 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #3
0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 1024 KB Output is correct
2 Correct 12 ms 1180 KB Output is correct
3 Incorrect 11 ms 1152 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #4
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 1024 KB Output is correct
2 Correct 12 ms 1180 KB Output is correct
3 Incorrect 11 ms 1152 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 640 KB Output is correct
2 Correct 2 ms 768 KB Output is correct
3 Correct 2 ms 640 KB Output is correct
4 Correct 3 ms 768 KB Output is correct
5 Correct 2 ms 640 KB Output is correct
6 Correct 2 ms 768 KB Output is correct
7 Correct 2 ms 768 KB Output is correct
8 Correct 2 ms 688 KB Output is correct
9 Correct 2 ms 640 KB Output is correct
10 Correct 2 ms 640 KB Output is correct
11 Correct 2 ms 512 KB Output is correct
12 Correct 2 ms 512 KB Output is correct
13 Correct 2 ms 512 KB Output is correct
14 Correct 2 ms 512 KB Output is correct
15 Correct 2 ms 512 KB Output is correct
16 Correct 10 ms 1024 KB Output is correct
17 Correct 12 ms 1180 KB Output is correct
18 Incorrect 11 ms 1152 KB Output isn't correct
19 Halted 0 ms 0 KB -