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답안 #1066306

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1066306 2024-08-19T17:40:57 Z Serendipity__ 공룡 발자국 (KOI18_footprint) C++17
100 / 100
 802 ms 114004 KB 
/*###############################################################################################################
##                                    Author : Kim Tae Yoon (Serendipity__)                                    ##
###############################################################################################################*/

#include <bits/stdc++.h>
#define fastio std::ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define prntyes cout<<"Yes\n";
#define prntno cout<<"No\n";
using namespace std;
// mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count()); // random int64 generator
typedef long long ll;
typedef unsigned long ul;
typedef unsigned long long ull;
typedef __int128 ll128;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pii;
typedef complex<double> inum;
// Macros from KACTL pdf
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef vector<int> vi;
typedef vector<double> vd;
const double PI = acos(-1);
const int INF = 0x3f3f3f3f;
const ll LLINF = 1000000000000000000LL;
const ll MAX = 200005; // depending on the problem
const ll MOD = 998244353; // depending on the problem


template <class T> int sgn(T x) { return (x > 0) - (x < 0); }
template<class T>
struct Point {
    typedef Point P;
    T x, y;
    explicit Point(T x=0, T y=0) : x(x), y(y) {}
    bool operator<(P p) const { return tie(x,y) < tie(p.x,p.y); }
    bool operator==(P p) const { return tie(x,y)==tie(p.x,p.y); }
    P operator+(P p) const { return P(x+p.x, y+p.y); }
    P operator-(P p) const { return P(x-p.x, y-p.y); }
    P operator*(T d) const { return P(x*d, y*d); }
    P operator/(T d) const { return P(x/d, y/d); }
    T dot(P p) const { return x*p.x + y*p.y; }
    T cross(P p) const { return x*p.y - y*p.x; }
    T cross(P a, P b) const { return (a-*this).cross(b-*this); }
    T dist2() const { return x*x + y*y; }
    double dist() const { return sqrt((double)dist2()); }
    // angle to x-axis in interval [-pi, pi]
    double angle() const { return atan2(y, x); }
    P unit() const { return *this/dist(); } // makes dist()=1
    P perp() const { return P(-y, x); } // rotates +90 degrees
    P normal() const { return perp().unit(); }
    // returns point rotated 'a' radians ccw around the origin
    P rotate(double a) const {
        return P(x*cos(a)-y*sin(a),x*sin(a)+y*cos(a)); }
    friend ostream& operator<<(ostream& os, P p) {
        return os << "(" << p.x << "," << p.y << ")"; }
};
typedef Point<ll> P;

int dp[2][3005][3005];
int track[2][3005][3005];

void solve() {
    ll N; cin>>N;
    vector<P> A(N);
    for (int i=0;i<N;i++){
        ll x,y; cin>>x>>y;
        A[i] = P(x,y);
    }

    int s = 0;
    for (int i=1;i<N;i++){
        if (A[i].y < A[s].y){
            s = i;
        }
    }
    swap(A[0], A[s]);
    ll dx,dy;
    dx = A[0].x;
    dy = A[0].y;
    for (int i=0;i<N;i++){
        A[i].x -= dx;
        A[i].y -= dy;
    }

    sort(A.begin()+1, A.end(), [&](P l, P r){
        return l.cross(r) > 0;
    });

    for (int j=N-1;j>=1;j--){
        vector<int> L,R;
        for (int i=0;i<N;i++){
            if (A[j].cross(A[i]) > 0){
                L.push_back(i);
            }else if (A[j].cross(A[i]) < 0){
                R.push_back(i);
            }
        }

        sort(L.begin(), L.end(), [&](int l, int r){
            return A[j].cross(A[l],A[r]) > 0;
        });
        sort(R.begin(), R.end(), [&](int l, int r){
            return A[j].cross(A[l],A[r]) > 0;
        });

        int ls = L.size();
        int rs = R.size();
        int p;

        // ccw = 0
        p = 0;
        int mx = -INF;
        int pos = -1;
        for (int t=0;t<rs;t++){
            int i = R[t];
            while(p<ls){
                int k = L[p];
                if (A[j].cross(A[i],A[k]) > 0){
                    if (mx < dp[1][k][j]+1){
                        mx = dp[1][k][j]+1;
                        pos = k;
                    }
                    ++p; 
                }else{
                    break;
                }
            }
            dp[0][j][i] = mx;
            track[0][j][i] = pos;
        }

        // ccw = 1
        p = ls-1;
        mx = 2;
        pos = -1;
        for (int t=rs-1;t>=0;t--){
            int i = R[t];
            while(p>=0){
                int k = L[p];
                if (A[j].cross(A[i],A[k]) < 0){
                    if (mx < dp[0][k][j]+1){
                        mx = dp[0][k][j]+1;
                        pos = k;
                    }
                    --p;
                }else{
                    break;
                }
            }
            dp[1][j][i] = mx;
            track[1][j][i] = pos;
        }
    }

    int ans = 0;
    int s1,s2,t=0;
    for (int i=1;i<N;i++){
        for (int j=i+1;j<N;j++){
            if (dp[0][j][i]+1 > ans){
                ans = dp[0][j][i]+1;
                s1 = j;
                s2 = i;
            }
        }
    }
    if (ans < 4){cout<<0; return;}

    for (int i=0;i<N;i++){
        A[i].x += dx;
        A[i].y += dy;
    }

    cout<<ans<<"\n";
    cout<<A[0].x<<" "<<A[0].y<<"\n";
    cout<<A[s2].x<<" "<<A[s2].y<<"\n";
    while(1){
        if (s1==-1){break;}
        cout<<A[s1].x<<" "<<A[s1].y<<"\n";
        tie(s1,s2) = pi(track[t][s1][s2],s1);
        t^=1;
    }

}

int main() {
    fastio;
    int tc = 1;
    // cin >> tc;
    while (tc--) {
        solve();
    }
    return 0;
}

Compilation message

footprint.cpp: In function 'void solve()':
footprint.cpp:178:15: warning: 's2' may be used uninitialized in this function [-Wmaybe-uninitialized]
  178 |     cout<<A[s2].x<<" "<<A[s2].y<<"\n";
      |               ^

Subtask #1
14.0 / 14.0

# 결과 실행 시간 메모리 Grader output
1 Correct 651 ms 103948 KB Output is correct
2 Correct 684 ms 105832 KB Output is correct
3 Correct 663 ms 103852 KB Output is correct
4 Correct 685 ms 105564 KB Output is correct
5 Correct 670 ms 105580 KB Output is correct
6 Correct 670 ms 105832 KB Output is correct
7 Correct 682 ms 105828 KB Output is correct
8 Correct 680 ms 105800 KB Output is correct
9 Correct 677 ms 105812 KB Output is correct
10 Correct 687 ms 105556 KB Output is correct
11 Correct 688 ms 105828 KB Output is correct
12 Correct 682 ms 105760 KB Output is correct
13 Correct 710 ms 107616 KB Output is correct
14 Correct 663 ms 105552 KB Output is correct
15 Correct 651 ms 103784 KB Output is correct

Subtask #2
12.0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 6492 KB Output is correct
2 Correct 1 ms 6492 KB Output is correct
3 Correct 1 ms 6492 KB Output is correct
4 Correct 1 ms 6492 KB Output is correct
5 Correct 1 ms 6492 KB Output is correct
6 Correct 1 ms 6492 KB Output is correct
7 Correct 1 ms 6492 KB Output is correct
8 Correct 1 ms 6492 KB Output is correct
9 Correct 1 ms 6492 KB Output is correct
10 Correct 1 ms 6492 KB Output is correct
11 Correct 1 ms 6492 KB Output is correct
12 Correct 1 ms 6492 KB Output is correct
13 Correct 1 ms 6492 KB Output is correct
14 Correct 1 ms 6492 KB Output is correct
15 Correct 1 ms 6492 KB Output is correct
16 Correct 1 ms 6492 KB Output is correct
17 Correct 1 ms 6520 KB Output is correct
18 Correct 1 ms 6492 KB Output is correct
19 Correct 1 ms 6492 KB Output is correct
20 Correct 1 ms 6492 KB Output is correct

Subtask #3
29.0 / 29.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 6492 KB Output is correct
2 Correct 1 ms 6492 KB Output is correct
3 Correct 1 ms 6492 KB Output is correct
4 Correct 1 ms 6492 KB Output is correct
5 Correct 1 ms 6492 KB Output is correct
6 Correct 1 ms 6492 KB Output is correct
7 Correct 1 ms 6492 KB Output is correct
8 Correct 1 ms 6492 KB Output is correct
9 Correct 1 ms 6492 KB Output is correct
10 Correct 1 ms 6492 KB Output is correct
11 Correct 1 ms 6492 KB Output is correct
12 Correct 1 ms 6492 KB Output is correct
13 Correct 1 ms 6492 KB Output is correct
14 Correct 1 ms 6492 KB Output is correct
15 Correct 1 ms 6492 KB Output is correct
16 Correct 1 ms 6492 KB Output is correct
17 Correct 1 ms 6520 KB Output is correct
18 Correct 1 ms 6492 KB Output is correct
19 Correct 1 ms 6492 KB Output is correct
20 Correct 1 ms 6492 KB Output is correct
21 Correct 6 ms 18780 KB Output is correct
22 Correct 9 ms 18904 KB Output is correct
23 Correct 6 ms 18940 KB Output is correct
24 Correct 7 ms 21004 KB Output is correct
25 Correct 7 ms 20948 KB Output is correct
26 Correct 8 ms 20828 KB Output is correct
27 Correct 7 ms 20828 KB Output is correct
28 Correct 7 ms 20828 KB Output is correct
29 Correct 7 ms 20984 KB Output is correct
30 Correct 8 ms 20828 KB Output is correct
31 Correct 7 ms 20828 KB Output is correct
32 Correct 7 ms 21000 KB Output is correct
33 Correct 4 ms 20828 KB Output is correct
34 Correct 4 ms 20828 KB Output is correct
35 Correct 5 ms 20828 KB Output is correct

Subtask #4
45.0 / 45.0

# 결과 실행 시간 메모리 Grader output
1 Correct 651 ms 103948 KB Output is correct
2 Correct 684 ms 105832 KB Output is correct
3 Correct 663 ms 103852 KB Output is correct
4 Correct 685 ms 105564 KB Output is correct
5 Correct 670 ms 105580 KB Output is correct
6 Correct 670 ms 105832 KB Output is correct
7 Correct 682 ms 105828 KB Output is correct
8 Correct 680 ms 105800 KB Output is correct
9 Correct 677 ms 105812 KB Output is correct
10 Correct 687 ms 105556 KB Output is correct
11 Correct 688 ms 105828 KB Output is correct
12 Correct 682 ms 105760 KB Output is correct
13 Correct 710 ms 107616 KB Output is correct
14 Correct 663 ms 105552 KB Output is correct
15 Correct 651 ms 103784 KB Output is correct
16 Correct 1 ms 6492 KB Output is correct
17 Correct 1 ms 6492 KB Output is correct
18 Correct 1 ms 6492 KB Output is correct
19 Correct 1 ms 6492 KB Output is correct
20 Correct 1 ms 6492 KB Output is correct
21 Correct 1 ms 6492 KB Output is correct
22 Correct 1 ms 6492 KB Output is correct
23 Correct 1 ms 6492 KB Output is correct
24 Correct 1 ms 6492 KB Output is correct
25 Correct 1 ms 6492 KB Output is correct
26 Correct 1 ms 6492 KB Output is correct
27 Correct 1 ms 6492 KB Output is correct
28 Correct 1 ms 6492 KB Output is correct
29 Correct 1 ms 6492 KB Output is correct
30 Correct 1 ms 6492 KB Output is correct
31 Correct 1 ms 6492 KB Output is correct
32 Correct 1 ms 6520 KB Output is correct
33 Correct 1 ms 6492 KB Output is correct
34 Correct 1 ms 6492 KB Output is correct
35 Correct 1 ms 6492 KB Output is correct
36 Correct 6 ms 18780 KB Output is correct
37 Correct 9 ms 18904 KB Output is correct
38 Correct 6 ms 18940 KB Output is correct
39 Correct 7 ms 21004 KB Output is correct
40 Correct 7 ms 20948 KB Output is correct
41 Correct 8 ms 20828 KB Output is correct
42 Correct 7 ms 20828 KB Output is correct
43 Correct 7 ms 20828 KB Output is correct
44 Correct 7 ms 20984 KB Output is correct
45 Correct 8 ms 20828 KB Output is correct
46 Correct 7 ms 20828 KB Output is correct
47 Correct 7 ms 21000 KB Output is correct
48 Correct 4 ms 20828 KB Output is correct
49 Correct 4 ms 20828 KB Output is correct
50 Correct 5 ms 20828 KB Output is correct
51 Correct 658 ms 105556 KB Output is correct
52 Correct 665 ms 105556 KB Output is correct
53 Correct 659 ms 107604 KB Output is correct
54 Correct 761 ms 113576 KB Output is correct
55 Correct 765 ms 113644 KB Output is correct
56 Correct 802 ms 113492 KB Output is correct
57 Correct 761 ms 113496 KB Output is correct
58 Correct 771 ms 113528 KB Output is correct
59 Correct 781 ms 113372 KB Output is correct
60 Correct 758 ms 113524 KB Output is correct
61 Correct 761 ms 113492 KB Output is correct
62 Correct 772 ms 113496 KB Output is correct
63 Correct 276 ms 113492 KB Output is correct
64 Correct 286 ms 113492 KB Output is correct
65 Correct 288 ms 113492 KB Output is correct
66 Correct 489 ms 113560 KB Output is correct
67 Correct 479 ms 114004 KB Output is correct
68 Correct 465 ms 113544 KB Output is correct