Submission #601205

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
601205	2022-07-21T13:07:09 Z	MilosMilutinovic	Fountain Parks (IOI21_parks)	C++17	5 / 100	571 ms	39768 KB

parks

/**
 *    author:  wxhtzdy
 *    created: 21.07.2022 14:34:57
**/
/* 
  First idea was 2SAT having verteces (road, direction), but there always exist constructive idea...
  https://oj.uz/submission/437652 
*/
#include "parks.h"
#include <bits/stdc++.h>

using namespace std;

const int dx[] = {2, 0, -2, 0};
const int dy[] = {0, 2, 0, -2};

class dsu {
  public:
  vector<int> p;
  int n;
  dsu(int _n) : n(_n) {
    p.resize(n);
    iota(p.begin(), p.end(), 0);
  }
  inline int get(int x) {
    return (x == p[x] ? x : (p[x] = get(p[x])));
  }
  inline bool unite(int x, int y) {
    x = get(x);
    y = get(y);
    if (x != y) {
      p[x] = y;
      return true;
    }
    return false;
  }
};

int construct_roads(vector<int> x, vector<int> y) {
  int n = (int) x.size();
  map<pair<int, int>, int> mp;
  for (int i = 0; i < n; i++) {
    mp[{x[i], y[i]}] = i;
  }
  vector<vector<int>> id(n, vector<int>(4, -1));
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < 4; j++) {
      int nx = x[i] + dx[j];
      int ny = y[i] + dy[j];
      if (mp.count({nx, ny})) {
        id[i][j] = mp[{nx, ny}];        
      }
    }
  }
  dsu d(n);
  vector<int> u, v;
  vector<int> a, b;
  auto Add = [&](int i, int j) {
    d.unite(i, j);
    u.push_back(i);
    v.push_back(j);
    if (x[i] == x[j]) {
      b.push_back(y[i] + y[j] >> 1);
      if ((x[i] + y[i]) % 2 == 1) {
        a.push_back(x[i] - 1);
      } else {
        a.push_back(x[i] + 1);
      }
    } else {
      a.push_back(x[i] + x[j] >> 1);
      if ((x[i] + y[i]) % 2 == 1) {
        b.push_back(y[i] + 1);
      } else {
        b.push_back(y[i] - 1);
      }
    }
  };
  for (int i = 0; i < n; i++) {
    int i0 = id[i][0], i1 = id[i][1];
    if (i0 == -1 && i1 == -1) {
      continue;
    }
    if (i0 == -1) {
      Add(i, i1);
      continue;
    }
    if (i1 == -1) {
      Add(i, i0);
      continue;
    }
    if (d.get(i0) != d.get(i1)) {
      Add(i, i0);
      Add(i, i1);
    } else {
      if ((x[i] + y[i]) % 2 == 1) {
        Add(i, i0);
      } else {
        Add(i, i1);
      }
    }
  }
  if ((int) u.size() != n - 1) {
    return 0;    
  }
  build(u, v, a, b);
  return 1;
}

Compilation message

parks.cpp: In lambda function:
parks.cpp:63:24: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   63 |       b.push_back(y[i] + y[j] >> 1);
parks.cpp:70:24: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   70 |       a.push_back(x[i] + x[j] >> 1);

Subtask #1

5.0 / 5.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	212 KB	Output is correct
2	Correct	1 ms	212 KB	Output is correct
3	Correct	1 ms	212 KB	Output is correct
4	Correct	1 ms	212 KB	Output is correct
5	Correct	1 ms	296 KB	Output is correct
6	Correct	1 ms	212 KB	Output is correct
7	Correct	1 ms	212 KB	Output is correct
8	Correct	1 ms	212 KB	Output is correct
9	Correct	184 ms	19652 KB	Output is correct
10	Correct	12 ms	2260 KB	Output is correct
11	Correct	82 ms	10692 KB	Output is correct
12	Correct	18 ms	3180 KB	Output is correct
13	Correct	47 ms	7556 KB	Output is correct
14	Correct	1 ms	340 KB	Output is correct
15	Correct	2 ms	580 KB	Output is correct
16	Correct	193 ms	19652 KB	Output is correct

Subtask #2

0 / 10.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	212 KB	Output is correct
2	Correct	1 ms	212 KB	Output is correct
3	Correct	1 ms	212 KB	Output is correct
4	Correct	1 ms	212 KB	Output is correct
5	Correct	1 ms	296 KB	Output is correct
6	Correct	1 ms	212 KB	Output is correct
7	Correct	1 ms	212 KB	Output is correct
8	Correct	1 ms	212 KB	Output is correct
9	Correct	184 ms	19652 KB	Output is correct
10	Correct	12 ms	2260 KB	Output is correct
11	Correct	82 ms	10692 KB	Output is correct
12	Correct	18 ms	3180 KB	Output is correct
13	Correct	47 ms	7556 KB	Output is correct
14	Correct	1 ms	340 KB	Output is correct
15	Correct	2 ms	580 KB	Output is correct
16	Correct	193 ms	19652 KB	Output is correct
17	Incorrect	1 ms	212 KB	Tree @(3, 3) appears more than once: for edges on positions 0 and 2
18	Halted	0 ms	0 KB	-

Subtask #3

0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	212 KB	Output is correct
2	Correct	1 ms	212 KB	Output is correct
3	Correct	1 ms	212 KB	Output is correct
4	Correct	1 ms	212 KB	Output is correct
5	Correct	1 ms	296 KB	Output is correct
6	Correct	1 ms	212 KB	Output is correct
7	Correct	1 ms	212 KB	Output is correct
8	Correct	1 ms	212 KB	Output is correct
9	Correct	184 ms	19652 KB	Output is correct
10	Correct	12 ms	2260 KB	Output is correct
11	Correct	82 ms	10692 KB	Output is correct
12	Correct	18 ms	3180 KB	Output is correct
13	Correct	47 ms	7556 KB	Output is correct
14	Correct	1 ms	340 KB	Output is correct
15	Correct	2 ms	580 KB	Output is correct
16	Correct	193 ms	19652 KB	Output is correct
17	Incorrect	1 ms	212 KB	Tree @(3, 3) appears more than once: for edges on positions 0 and 2
18	Halted	0 ms	0 KB	-

Subtask #4

0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	212 KB	Output is correct
2	Correct	1 ms	212 KB	Output is correct
3	Correct	1 ms	212 KB	Output is correct
4	Correct	1 ms	212 KB	Output is correct
5	Correct	1 ms	296 KB	Output is correct
6	Correct	1 ms	212 KB	Output is correct
7	Correct	1 ms	212 KB	Output is correct
8	Correct	1 ms	212 KB	Output is correct
9	Correct	184 ms	19652 KB	Output is correct
10	Correct	12 ms	2260 KB	Output is correct
11	Correct	82 ms	10692 KB	Output is correct
12	Correct	18 ms	3180 KB	Output is correct
13	Correct	47 ms	7556 KB	Output is correct
14	Correct	1 ms	340 KB	Output is correct
15	Correct	2 ms	580 KB	Output is correct
16	Correct	193 ms	19652 KB	Output is correct
17	Correct	1 ms	212 KB	Output is correct
18	Correct	1 ms	232 KB	Output is correct
19	Correct	1 ms	212 KB	Output is correct
20	Correct	571 ms	39768 KB	Output is correct
21	Incorrect	527 ms	39536 KB	Tree @(43593, 43597) appears more than once: for edges on positions 161 and 532
22	Halted	0 ms	0 KB	-

Subtask #5

0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	212 KB	Output is correct
2	Correct	1 ms	212 KB	Output is correct
3	Correct	1 ms	212 KB	Output is correct
4	Correct	1 ms	212 KB	Output is correct
5	Correct	1 ms	296 KB	Output is correct
6	Correct	1 ms	212 KB	Output is correct
7	Correct	1 ms	212 KB	Output is correct
8	Correct	1 ms	212 KB	Output is correct
9	Correct	184 ms	19652 KB	Output is correct
10	Correct	12 ms	2260 KB	Output is correct
11	Correct	82 ms	10692 KB	Output is correct
12	Correct	18 ms	3180 KB	Output is correct
13	Correct	47 ms	7556 KB	Output is correct
14	Correct	1 ms	340 KB	Output is correct
15	Correct	2 ms	580 KB	Output is correct
16	Correct	193 ms	19652 KB	Output is correct
17	Incorrect	406 ms	33000 KB	Solution announced impossible, but it is possible.
18	Halted	0 ms	0 KB	-

Subtask #6

0 / 30.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	212 KB	Output is correct
2	Correct	1 ms	212 KB	Output is correct
3	Correct	1 ms	212 KB	Output is correct
4	Correct	1 ms	212 KB	Output is correct
5	Correct	1 ms	296 KB	Output is correct
6	Correct	1 ms	212 KB	Output is correct
7	Correct	1 ms	212 KB	Output is correct
8	Correct	1 ms	212 KB	Output is correct
9	Correct	184 ms	19652 KB	Output is correct
10	Correct	12 ms	2260 KB	Output is correct
11	Correct	82 ms	10692 KB	Output is correct
12	Correct	18 ms	3180 KB	Output is correct
13	Correct	47 ms	7556 KB	Output is correct
14	Correct	1 ms	340 KB	Output is correct
15	Correct	2 ms	580 KB	Output is correct
16	Correct	193 ms	19652 KB	Output is correct
17	Incorrect	1 ms	212 KB	Tree @(3, 3) appears more than once: for edges on positions 0 and 2
18	Halted	0 ms	0 KB	-