oj.uz

Submission #498604

# Submission time Handle Problem Language Result Execution time Memory
498604 2021-12-25T17:39:28 Z 600Mihnea Skyscraper (JOI16_skyscraper) C++17
20 / 100
 1874 ms 25668 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int M = (int) 1e9 + 7;

int add(int a, int b) {
  a += b;
  if (a >= M) return a - M;
  if (a < 0) return a + M;
  return a;
}

int mul(int a, int b) {
  return a * (ll) b % M;
}

void addup(int &a, int b) {
  a = add(a, b);
}

void mulup(int &a, int b) {
  a = mul(a, b);
}

const int N = 100 + 7;
const int Z = 4000 + 7;
int n;
int limit;
int a[N];
int dp[N][2 * Z][2][2]; /// ways[islands][sum]
int nwdp[N][2 * Z][2][2];

void rst() {
  for (int i = 0; i <= n; i++) {
    for (int j = 0; j < 2 * Z; j++) {
      for (int bg = 0; bg < 2; bg++) {
        for (int nd = 0; nd < 2; nd++) {
          dp[i][j][bg][nd] = nwdp[i][j][bg][nd];
          nwdp[i][j][bg][nd] = 0;
        }
      }
    }
  }
}

void addTo(int islands, int real_sum, int bg, int nd, int value) {
  if (islands >= 1 && -(Z - 1) <= real_sum && real_sum <= (Z - 1)) {
    addup(nwdp[islands][real_sum + Z][bg][nd], value);
  }
}

int main() {
  bool isHome;

  isHome = true;
  isHome = false;

  if (isHome) {
    freopen ("input", "r", stdin);
  } else {
    ios::sync_with_stdio(0); cin.tie(0);
  }


  cin >> n >> limit;


  if (n == 1) {
    cout << "1\n";
    return 0;
  }

  for (int i = 1; i <= n; i++) {
    cin >> a[i];
  }
  sort(a + 1, a + n + 1);

  /// it is the first

  dp[1][Z - a[1]][1][0] = 1;

  /// it is the last


  dp[1][Z - a[1]][0][1] = 1;

  /// it is in the middle


  dp[1][Z - 2 * a[1]][0][0] = 1;

  for (int it = 2; it <= n; it++) {
    int x = a[it];
    for (int islands = 1; islands < it; islands++) {
      for (int sum = -(Z - 1); sum <= (Z - 1); sum++) {
        for (int bg = 0; bg < 2; bg++) {
          for (int nd = 0; nd < 2; nd++) {
            int dp_value = dp[islands][sum + Z][bg][nd];
            if (dp_value == 0) {
              continue;
            }

            { /// create a new island

              /// make it the first

              if (bg == 0) {
                addTo(islands + 1, sum - x, 1, nd, dp_value);
              }

              /// make it the last

              if (nd == 0) {
                addTo(islands + 1, sum - x, bg, 1, dp_value);
              }

              /// place it in the middle

              int total_ways = (islands + 1) - bg - nd;

              addTo(islands + 1, sum - 2 * x, bg, nd, mul(dp_value, total_ways));

            }

            { /// put it next to some guy


              /// make it the first

              if (bg == 0) {
                addTo(islands, sum + x, 1, nd, dp_value);
              }

              /// make it the last

              if (nd == 0) {
                addTo(islands, sum + x, bg, 1, dp_value);
              }


              /// place it in the middle

              int total_ways = 2 * islands - bg - nd;

              addTo(islands, sum, bg, nd, mul(dp_value, total_ways));

            }

            if (islands >= 2) { /// join some guys

              int total_ways = (islands - 1);

              addTo(islands - 1, sum + 2 * x, bg, nd, mul(dp_value, total_ways));
            }

          }
        }
      }
    }
    rst();
  }


  int sol = 0;

  for (int sum = 0; sum <= limit; sum++) {
    int dp_value = dp[1][sum + Z][1][1];
    if (dp_value) {
      addup(sol, dp_value);
    }
  }

  cout << sol << "\n";


  return 0;
}

Compilation message

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:62:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |     freopen ("input", "r", stdin);
      |     ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 972 KB Output is correct
3 Correct 1 ms 1228 KB Output is correct
4 Correct 3 ms 1996 KB Output is correct
5 Correct 5 ms 2508 KB Output is correct
6 Correct 5 ms 2508 KB Output is correct
7 Correct 5 ms 2508 KB Output is correct
8 Correct 5 ms 2508 KB Output is correct
9 Correct 5 ms 2508 KB Output is correct
10 Correct 5 ms 2520 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 3532 KB Output is correct
2 Correct 16 ms 4100 KB Output is correct
3 Correct 14 ms 4044 KB Output is correct
4 Correct 17 ms 4096 KB Output is correct
5 Correct 15 ms 4092 KB Output is correct
6 Correct 17 ms 4044 KB Output is correct
7 Correct 13 ms 4096 KB Output is correct
8 Correct 12 ms 4096 KB Output is correct
9 Correct 13 ms 4044 KB Output is correct
10 Correct 16 ms 4044 KB Output is correct

Subtask #3
0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 972 KB Output is correct
3 Correct 1 ms 1228 KB Output is correct
4 Correct 3 ms 1996 KB Output is correct
5 Correct 5 ms 2508 KB Output is correct
6 Correct 5 ms 2508 KB Output is correct
7 Correct 5 ms 2508 KB Output is correct
8 Correct 5 ms 2508 KB Output is correct
9 Correct 5 ms 2508 KB Output is correct
10 Correct 5 ms 2520 KB Output is correct
11 Correct 10 ms 3532 KB Output is correct
12 Correct 16 ms 4100 KB Output is correct
13 Correct 14 ms 4044 KB Output is correct
14 Correct 17 ms 4096 KB Output is correct
15 Correct 15 ms 4092 KB Output is correct
16 Correct 17 ms 4044 KB Output is correct
17 Correct 13 ms 4096 KB Output is correct
18 Correct 12 ms 4096 KB Output is correct
19 Correct 13 ms 4044 KB Output is correct
20 Correct 16 ms 4044 KB Output is correct
21 Correct 134 ms 10604 KB Output is correct
22 Correct 1012 ms 20140 KB Output is correct
23 Correct 1765 ms 25668 KB Output is correct
24 Incorrect 1874 ms 25548 KB Output isn't correct
25 Halted 0 ms 0 KB -