oj.uz

Submission #1009779

# Submission time Handle Problem Language Result Execution time Memory
1009779 2024-06-28T04:21:12 Z asdfgrace Palembang Bridges (APIO15_bridge) C++17
22 / 100
 30 ms 4860 KB 
#include <bits/stdc++.h>
using namespace std;

#define dbg(x) x
#define prt(x) dbg(cerr << x)
#define pv(x) dbg(cerr << #x << " = " << x << '\n')
#define pv2(x) dbg(cerr << #x << " = " << x.first << ',' << x.second << '\n')
#define parr(x) dbg(prt(#x << " = { "); for (auto y : x) prt(y << ' '); prt("}\n");)
#define parr2(x) dbg(prt(#x << " = { "); for (auto [y, z] : x) prt(y << ',' << z << "  "); prt("}\n");)
#define parr2d(x) dbg(prt(#x << ":\n"); for (auto arr : x) {parr(arr);} prt('\n'));
#define parr2d2(x) dbg(prt(#x << ":\n"); for (auto arr : x) {parr2(arr);} prt('\n'));

/*
build 1 or 2 bridges
add to baseline of sum of all distances driven without crossing bridge + n
then only consider people crossing

k=1:
minimize the sum of all abs(s[i] - x) + abs(t[i] - x)
one of the given locs is optimal
so here treat all s[i] and t[i] the same, sort, etc.

k=2:
if l <= x or y <= r, dist = r - l
else, dist = r - l + 2 * (dist btwn either end & closest bridge)
assume x < y
5 cases
1) left of x
2) contains x
3) btwn x, y
4) contains y
5) right of y
best y for each x?
everything to left/containing x is handled (i.e. everything with l <= x)
n^2 sol:
for (each i)
case 1: x = l[i]
everything true
case 2: x = r[i]

*/

int main() {
  ios::sync_with_stdio(0); cin.tie(0);
  int k, n;
  cin >> k >> n;
  vector<array<int, 2>> a;
  long long bsl = 0;
  for (int i = 0; i < n; i++) {
    char c1, c2; int i1, i2;
    cin >> c1 >> i1 >> c2 >> i2;
    if (c1 == c2) {
      bsl += abs(i2 - i1);
    } else {
      if (i2 < i1) swap(i1, i2);
      a.push_back({i1, i2});
      bsl++;
    }
  }
  n = (int) a.size();
  vector<int> b;
  for (int i = 0; i < n; i++) {
    b.push_back(a[i][0]); b.push_back(a[i][1]);
  }
  sort(b.begin(), b.end());
  if (k == 1) {
    long long sum = 0;
    for (int i = 0; i < 2 * n; i++) {
      sum += b[i] - b[0];
    }
    long long best = sum;
    for (int i = 1; i < 2 * n; i++) {
      sum += (long long) i * (b[i] - b[i - 1]);
      sum -= (long long) (2 * n - i) * (b[i] - b[i - 1]);
      best = min(best, sum);
    }
    cout << best + bsl << '\n'; 
  } else {
    long long best = 1e18;
    for (int x = 0; x < 2 * n; x++) {
      for (int y = x; y < 2 * n; y++) {
        long long sum = 0;
        for (int i = 0; i < n; i++) {
          sum += min(abs(a[i][0] - b[x]) + abs(a[i][1] - b[x]),
            abs(a[i][0] - b[y]) + abs(a[i][1] - b[y]));
        }
        best = min(best, sum);
      }
    }
    cout << best + bsl << '\n';
  }
}

/*
any observations help

check every line
IF YOUR LINES AREN'T WRONG
CHECK IF YOUR LINES ARE IN THE RIGHT ORDER

NEVER GIVE UP
*/

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 600 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 1 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct

Subtask #2
14.0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 344 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 1 ms 344 KB Output is correct
6 Correct 0 ms 344 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 1 ms 344 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 14 ms 3544 KB Output is correct
13 Correct 30 ms 4820 KB Output is correct
14 Correct 21 ms 3800 KB Output is correct
15 Correct 17 ms 2780 KB Output is correct
16 Correct 17 ms 4176 KB Output is correct
17 Correct 22 ms 4824 KB Output is correct
18 Correct 21 ms 4568 KB Output is correct
19 Correct 27 ms 4860 KB Output is correct
20 Correct 18 ms 4564 KB Output is correct
21 Correct 23 ms 4564 KB Output is correct

Subtask #3
0 / 9.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 348 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 32.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 348 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 37.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 348 KB Output isn't correct
2 Halted 0 ms 0 KB -