oj.uz

Submission #44044

# Submission time Handle Problem Language Result Execution time Memory
44044 2018-03-29T12:46:42 Z wxh010910 Fences (JOI18_fences) C++17
100 / 100
 136 ms 2408 KB 
#include <bits/stdc++.h>

using namespace std;

#define X first
#define Y second
#define mp make_pair
#define pb push_back
#define Debug(...) fprintf(stderr, __VA_ARGS__)

typedef long long LL;
typedef long double LD;
typedef unsigned int uint;
typedef pair <int, int> pii;
typedef unsigned long long uLL;

template <typename T> inline void Read(T &x) {
  char c = getchar();
  bool f = false;
  for (x = 0; !isdigit(c); c = getchar()) {
    if (c == '-') {
      f = true;
    }
  }
  for (; isdigit(c); c = getchar()) {
    x = x * 10 + c - '0';
  }
  if (f) {
    x = -x;
  }
}

template <typename T> inline bool CheckMax(T &a, const T &b) {
  return a < b ? a = b, true : false;
}

template <typename T> inline bool CheckMin(T &a, const T &b) {
  return a > b ? a = b, true : false;
}

const int N = 420;
const double eps = 1e-6;
const double inf = 1e9;

inline int Sgn(double x) {
  return fabs(x) < eps ? 0 : x > 0 ? 1 : -1;
}

inline int Cmp(double x, double y) {
  return Sgn(x - y);
}

inline bool Mid(double l, double r, double mid) {
  return Cmp(l, mid) * Cmp(r, mid) <= 0;
}

struct Point {
  double x, y;
  
  Point(double _x = 0, double _y = 0) {
    x = _x, y = _y;
  }
  
  Point operator + (const Point &b) const {
    return Point(x + b.x, y + b.y);
  }
  
  Point operator - (const Point &b) const {
    return Point(x - b.x, y - b.y);
  }
  
  Point operator * (const double &b) const {
    return Point(x * b, y * b);
  }
  
  Point operator / (const double &b) const {
    return Point(x / b, y / b);
  }
  
  double operator * (const Point &b) const {
    return x * b.x + y * b.y;
  }
  
  double operator ^ (const Point &b) const {
    return x * b.y - y * b.x;
  }
  
  bool operator == (const Point &b) const {
    return !Cmp(x, b.x) && !Cmp(y, b.y);
  }
  
  bool operator != (const Point &b) const {
    return Cmp(x, b.x) || Cmp(y, b.y);
  }
  
  inline double Len() {
    return x * x + y * y;
  }
} s(0, 0), t(1, 1000), r[4], p[N], q[N];

double ans, dis[N][N];
int n, m;

inline double Dis(Point x, Point y) {
  return sqrt((x - y).Len());
}

inline bool Mid(Point l, Point r, Point mid) {
  return Mid(l.x, r.x, mid.x) && Mid(l.y, r.y, mid.y);
}

inline Point Projection(Point p, Point q, Point x) {
  Point delta = q - p;
  return p + delta * ((x - p) * delta / delta.Len());
}

inline bool IntersectInterval(double l1, double r1, double l2, double r2) {
  if (l1 > r1) {
    swap(l1, r1);
  }
  if (l2 > r2) {
    swap(l2, r2);
  }
  return Cmp(r1, l2) > 0 && Cmp(r2, l1) > 0;
}

inline bool IntersectSegment(Point l1, Point r1, Point l2, Point r2) {
  if (!IntersectInterval(l1.x, r1.x, l2.x, r2.x) || !IntersectInterval(l1.y, r1.y, l2.y, r2.y)) {
    return false;
  }
  return Sgn((l2 - l1) ^ (r2 - l1)) * Sgn((l2 - r1) ^ (r2 - r1)) < 0 && Sgn((l1 - l2) ^ (r1 - l2)) * Sgn((l1 - r2) ^ (r1 - r2)) < 0;
}

inline bool Check(Point x, Point y) {
  for (int i = 0; i < 4;  ++i) {
    if (IntersectSegment(x, y, r[i], r[i + 1 & 3])) {
      return false;
    }
  }
  Point z = (x + y) / 2;
  if (z.x > -m && z.x < m && z.y > -m && z.y < m) {
    return false;
  }
  return true;
}

inline void AddEdge(int x, int y, double d) {
  if (IntersectSegment(x <= n ? p[x] : q[x - n], y <= n ? p[y] : q[y - n], s, t)) {
    CheckMin(dis[x][y + (n << 1)], d);
    CheckMin(dis[y][x + (n << 1)], d);
    CheckMin(dis[y + (n << 1)][x], d);
    CheckMin(dis[x + (n << 1)][y], d);
  } else {
    CheckMin(dis[x][y], d);
    CheckMin(dis[y][x], d);
    CheckMin(dis[x + (n << 1)][y + (n << 1)], d);
    CheckMin(dis[y + (n << 1)][x + (n << 1)], d);
  }
}

inline void AddEdge(int x, int y, double d, bool f) {
  if (f) {
    CheckMin(dis[x][y + (n << 1)], d);
    CheckMin(dis[y][x + (n << 1)], d);
    CheckMin(dis[y + (n << 1)][x], d);
    CheckMin(dis[x + (n << 1)][y], d);
  } else {
    CheckMin(dis[x][y], d);
    CheckMin(dis[y][x], d);
    CheckMin(dis[x + (n << 1)][y + (n << 1)], d);
    CheckMin(dis[y + (n << 1)][x + (n << 1)], d);
  }
}

int main() {
#ifdef wxh010910
  freopen("d.in", "r", stdin);
#endif
  Read(n), Read(m), ans = m << 3;
  for (int i = 1; i <= n; ++i) {
    Read(p[i].x), Read(p[i].y), Read(q[i].x), Read(q[i].y);
  }
  r[0] = Point(m, m), r[1] = Point(m, -m), r[2] = Point(-m, -m), r[3] = Point(-m, m);
  for (int i = 0; i < 4; ++i) {
    ++n, p[n] = q[n] = r[i];
  }
  for (int i = 1; i <= n << 2; ++i) {
    for (int j = 1; j <= n << 2; ++j) {
      dis[i][j] = i == j ? 0 : inf;
    }
  }
  for (int i = 1; i <= n; ++i) {
    AddEdge(i, i + n, 0);
    for (int j = 1; j < i; ++j) {
      if (Check(p[i], p[j])) {
        AddEdge(i, j, Dis(p[i], p[j]));
      }
      if (Check(p[i], q[j])) {
        AddEdge(i, j + n, Dis(p[i], q[j]));
      }
      if (Check(q[i], p[j])) {
        AddEdge(i + n, j, Dis(q[i], p[j]));
      }
      if (Check(q[i], q[j])) {
        AddEdge(i + n, j + n, Dis(q[i], q[j]));
      }
      Point tmp;
      tmp = Projection(p[j], q[j], p[i]);
      if (Mid(p[j], q[j], tmp) && Check(p[i], tmp)) {
        AddEdge(i, j, Dis(p[i], tmp), IntersectSegment(p[i], tmp, s, t) ^ IntersectSegment(p[j], tmp, s, t));
        AddEdge(i, j + n, Dis(p[i], tmp), IntersectSegment(p[i], tmp, s, t) ^ IntersectSegment(q[j], tmp, s, t));
      }
      tmp = Projection(p[j], q[j], q[i]);
      if (Mid(p[j], q[j], tmp) && Check(q[i], tmp)) {
        AddEdge(i + n, j, Dis(q[i], tmp), IntersectSegment(q[i], tmp, s, t) ^ IntersectSegment(p[j], tmp, s, t));
        AddEdge(i + n, j + n, Dis(q[i], tmp), IntersectSegment(q[i], tmp, s, t) ^ IntersectSegment(q[j], tmp, s, t));
      }
      swap(i, j);
      tmp = Projection(p[j], q[j], p[i]);
      if (Mid(p[j], q[j], tmp) && Check(p[i], tmp)) {
        AddEdge(i, j, Dis(p[i], tmp), IntersectSegment(p[i], tmp, s, t) ^ IntersectSegment(p[j], tmp, s, t));
        AddEdge(i, j + n, Dis(p[i], tmp), IntersectSegment(p[i], tmp, s, t) ^ IntersectSegment(q[j], tmp, s, t));
      }
      tmp = Projection(p[j], q[j], q[i]);
      if (Mid(p[j], q[j], tmp) && Check(q[i], tmp)) {
        AddEdge(i + n, j, Dis(q[i], tmp), IntersectSegment(q[i], tmp, s, t) ^ IntersectSegment(p[j], tmp, s, t));
        AddEdge(i + n, j + n, Dis(q[i], tmp), IntersectSegment(q[i], tmp, s, t) ^ IntersectSegment(q[j], tmp, s, t));
      }
      swap(i, j);
    }
  }
  for (int k = 1; k <= n << 2; ++k) {
    for (int i = 1; i <= n << 2; ++i) {
      for (int j = 1; j <= n << 2; ++j) {
        CheckMin(dis[i][j], dis[i][k] + dis[k][j]);
      }
    }
  }
  for (int i = 1; i <= n << 1; ++i) {
    CheckMin(ans, dis[i][i + (n << 1)]);
  }
  printf("%lf\n", ans);
#ifdef wxh010910
  Debug("My Time: %.3lfms\n", (double)clock() / CLOCKS_PER_SEC);
#endif
  return 0;
}

Compilation message

fences.cpp: In function 'bool Check(Point, Point)':
fences.cpp:136:42: warning: suggest parentheses around '+' in operand of '&' [-Wparentheses]
     if (IntersectSegment(x, y, r[i], r[i + 1 & 3])) {
                                        ~~^~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 488 KB Output is correct
3 Correct 2 ms 488 KB Output is correct
4 Correct 2 ms 488 KB Output is correct
5 Correct 2 ms 620 KB Output is correct
6 Correct 2 ms 620 KB Output is correct
7 Correct 2 ms 620 KB Output is correct
8 Correct 2 ms 620 KB Output is correct
9 Correct 2 ms 620 KB Output is correct
10 Correct 2 ms 728 KB Output is correct
11 Correct 2 ms 776 KB Output is correct
12 Correct 2 ms 776 KB Output is correct
13 Correct 2 ms 776 KB Output is correct
14 Correct 2 ms 776 KB Output is correct
15 Correct 2 ms 776 KB Output is correct
16 Correct 2 ms 780 KB Output is correct
17 Correct 2 ms 780 KB Output is correct
18 Correct 2 ms 784 KB Output is correct
19 Correct 2 ms 808 KB Output is correct
20 Correct 2 ms 812 KB Output is correct

Subtask #2
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 488 KB Output is correct
3 Correct 2 ms 488 KB Output is correct
4 Correct 2 ms 488 KB Output is correct
5 Correct 2 ms 620 KB Output is correct
6 Correct 2 ms 620 KB Output is correct
7 Correct 2 ms 620 KB Output is correct
8 Correct 2 ms 620 KB Output is correct
9 Correct 2 ms 620 KB Output is correct
10 Correct 2 ms 728 KB Output is correct
11 Correct 2 ms 776 KB Output is correct
12 Correct 2 ms 776 KB Output is correct
13 Correct 2 ms 776 KB Output is correct
14 Correct 2 ms 776 KB Output is correct
15 Correct 2 ms 776 KB Output is correct
16 Correct 2 ms 780 KB Output is correct
17 Correct 2 ms 780 KB Output is correct
18 Correct 2 ms 784 KB Output is correct
19 Correct 2 ms 808 KB Output is correct
20 Correct 2 ms 812 KB Output is correct
21 Correct 2 ms 820 KB Output is correct
22 Correct 2 ms 948 KB Output is correct
23 Correct 2 ms 952 KB Output is correct
24 Correct 2 ms 956 KB Output is correct
25 Correct 2 ms 960 KB Output is correct
26 Correct 2 ms 964 KB Output is correct
27 Correct 2 ms 968 KB Output is correct
28 Correct 2 ms 972 KB Output is correct
29 Correct 2 ms 976 KB Output is correct
30 Correct 2 ms 980 KB Output is correct
31 Correct 2 ms 984 KB Output is correct
32 Correct 2 ms 988 KB Output is correct
33 Correct 2 ms 992 KB Output is correct
34 Correct 2 ms 996 KB Output is correct
35 Correct 2 ms 1000 KB Output is correct
36 Correct 2 ms 1004 KB Output is correct
37 Correct 2 ms 1008 KB Output is correct
38 Correct 2 ms 1008 KB Output is correct
39 Correct 2 ms 1016 KB Output is correct
40 Correct 2 ms 1016 KB Output is correct
41 Correct 2 ms 1016 KB Output is correct
42 Correct 2 ms 1016 KB Output is correct
43 Correct 2 ms 1016 KB Output is correct

Subtask #3
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 488 KB Output is correct
3 Correct 2 ms 488 KB Output is correct
4 Correct 2 ms 488 KB Output is correct
5 Correct 2 ms 620 KB Output is correct
6 Correct 2 ms 620 KB Output is correct
7 Correct 2 ms 620 KB Output is correct
8 Correct 2 ms 620 KB Output is correct
9 Correct 2 ms 620 KB Output is correct
10 Correct 2 ms 728 KB Output is correct
11 Correct 2 ms 776 KB Output is correct
12 Correct 2 ms 776 KB Output is correct
13 Correct 2 ms 776 KB Output is correct
14 Correct 2 ms 776 KB Output is correct
15 Correct 2 ms 776 KB Output is correct
16 Correct 2 ms 780 KB Output is correct
17 Correct 2 ms 780 KB Output is correct
18 Correct 2 ms 784 KB Output is correct
19 Correct 2 ms 808 KB Output is correct
20 Correct 2 ms 812 KB Output is correct
21 Correct 2 ms 820 KB Output is correct
22 Correct 2 ms 948 KB Output is correct
23 Correct 2 ms 952 KB Output is correct
24 Correct 2 ms 956 KB Output is correct
25 Correct 2 ms 960 KB Output is correct
26 Correct 2 ms 964 KB Output is correct
27 Correct 2 ms 968 KB Output is correct
28 Correct 2 ms 972 KB Output is correct
29 Correct 2 ms 976 KB Output is correct
30 Correct 2 ms 980 KB Output is correct
31 Correct 2 ms 984 KB Output is correct
32 Correct 2 ms 988 KB Output is correct
33 Correct 2 ms 992 KB Output is correct
34 Correct 2 ms 996 KB Output is correct
35 Correct 2 ms 1000 KB Output is correct
36 Correct 2 ms 1004 KB Output is correct
37 Correct 2 ms 1008 KB Output is correct
38 Correct 2 ms 1008 KB Output is correct
39 Correct 2 ms 1016 KB Output is correct
40 Correct 2 ms 1016 KB Output is correct
41 Correct 2 ms 1016 KB Output is correct
42 Correct 2 ms 1016 KB Output is correct
43 Correct 2 ms 1016 KB Output is correct
44 Correct 107 ms 2316 KB Output is correct
45 Correct 103 ms 2320 KB Output is correct
46 Correct 97 ms 2320 KB Output is correct
47 Correct 98 ms 2408 KB Output is correct
48 Correct 102 ms 2408 KB Output is correct
49 Correct 101 ms 2408 KB Output is correct
50 Correct 136 ms 2408 KB Output is correct
51 Correct 99 ms 2408 KB Output is correct
52 Correct 104 ms 2408 KB Output is correct
53 Correct 105 ms 2408 KB Output is correct
54 Correct 97 ms 2408 KB Output is correct
55 Correct 112 ms 2408 KB Output is correct
56 Correct 102 ms 2408 KB Output is correct
57 Correct 100 ms 2408 KB Output is correct
58 Correct 97 ms 2408 KB Output is correct
59 Correct 99 ms 2408 KB Output is correct
60 Correct 110 ms 2408 KB Output is correct
61 Correct 109 ms 2408 KB Output is correct
62 Correct 2 ms 2408 KB Output is correct
63 Correct 2 ms 2408 KB Output is correct
64 Correct 106 ms 2408 KB Output is correct
65 Correct 113 ms 2408 KB Output is correct
66 Correct 97 ms 2408 KB Output is correct
67 Correct 92 ms 2408 KB Output is correct
68 Correct 89 ms 2408 KB Output is correct
69 Correct 97 ms 2408 KB Output is correct
70 Correct 84 ms 2408 KB Output is correct
71 Correct 93 ms 2408 KB Output is correct
72 Correct 89 ms 2408 KB Output is correct