oj.uz

Submission #498603

# Submission time Handle Problem Language Result Execution time Memory
498603 2021-12-25T17:39:05 Z 600Mihnea Skyscraper (JOI16_skyscraper) C++17
20 / 100
 815 ms 13004 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 = 2000 + 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 1 ms 324 KB Output is correct
2 Correct 1 ms 588 KB Output is correct
3 Correct 1 ms 716 KB Output is correct
4 Correct 2 ms 1100 KB Output is correct
5 Correct 3 ms 1356 KB Output is correct
6 Correct 3 ms 1344 KB Output is correct
7 Correct 3 ms 1348 KB Output is correct
8 Correct 2 ms 1356 KB Output is correct
9 Correct 3 ms 1356 KB Output is correct
10 Correct 3 ms 1356 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 1860 KB Output is correct
2 Correct 8 ms 2220 KB Output is correct
3 Correct 7 ms 2216 KB Output is correct
4 Correct 8 ms 2124 KB Output is correct
5 Correct 9 ms 2124 KB Output is correct
6 Correct 7 ms 2124 KB Output is correct
7 Correct 7 ms 2124 KB Output is correct
8 Correct 6 ms 2124 KB Output is correct
9 Correct 7 ms 2124 KB Output is correct
10 Correct 8 ms 2112 KB Output is correct

Subtask #3
0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 324 KB Output is correct
2 Correct 1 ms 588 KB Output is correct
3 Correct 1 ms 716 KB Output is correct
4 Correct 2 ms 1100 KB Output is correct
5 Correct 3 ms 1356 KB Output is correct
6 Correct 3 ms 1344 KB Output is correct
7 Correct 3 ms 1348 KB Output is correct
8 Correct 2 ms 1356 KB Output is correct
9 Correct 3 ms 1356 KB Output is correct
10 Correct 3 ms 1356 KB Output is correct
11 Correct 5 ms 1860 KB Output is correct
12 Correct 8 ms 2220 KB Output is correct
13 Correct 7 ms 2216 KB Output is correct
14 Correct 8 ms 2124 KB Output is correct
15 Correct 9 ms 2124 KB Output is correct
16 Correct 7 ms 2124 KB Output is correct
17 Correct 7 ms 2124 KB Output is correct
18 Correct 6 ms 2124 KB Output is correct
19 Correct 7 ms 2124 KB Output is correct
20 Correct 8 ms 2112 KB Output is correct
21 Correct 83 ms 5464 KB Output is correct
22 Correct 591 ms 10188 KB Output is correct
23 Correct 736 ms 13004 KB Output is correct
24 Incorrect 815 ms 13004 KB Output isn't correct
25 Halted 0 ms 0 KB -