Submission #1096531

#	Time	Username	Problem	Language	Result	Execution time	Memory
1096531		cpptowin	Skyscraper (JOI16_skyscraper)	C++17	100 / 100	94 ms	5980 KiB

skyscraper

#include <bits/stdc++.h>
#define fo(i, d, c) for (int i = d; i <= c; i++)
#define fod(i, c, d) for (int i = c; i >= d; i--)
#define maxn 1000010
#define N 1010
#define fi first
#define se second
#define pb emplace_back
#define en cout << "\n";
#define int long long
#define inf (int)1e18
#define bitcount(x) __builtin_popcountll(x)
#define pii pair<int, int>
#define vii vector<pii>
#define lb(x) x & -x
#define bit(i, j) ((i >> j) & 1)
#define offbit(i, j) (i ^ (1LL << j))
#define onbit(i, j) (i | (1LL << j))
#define vi vector<int>
#define all(x) x.begin(), x.end()
#define ss(x) (int)x.size()
template <typename T1, typename T2>
bool minimize(T1 &a, T2 b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <typename T1, typename T2>
bool maximize(T1 &a, T2 b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}
using namespace std;
const int nsqrt = 450;
const int mod = 1e9 + 7;
void add(int &x, int k)
{
    x += k;
    x %= mod;
    if (x < 0)
        x += mod;
}
void del(int &x, int k)
{
    x -= k;
    x %= mod;
    if (x < 0)
        x += mod;
}
int n, l, a[105];
int f[2][105][1111][3];
main()
{
#define name "TASK"
    if (fopen(name ".inp", "r"))
    {
        freopen(name ".inp", "r", stdin);
        freopen(name ".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n >> l;
    fo(i, 1, n) cin >> a[i];
    f[0][0][0][0] = 1;
    if(n == 1) return cout << 1,0;
    sort(a + 1, a + n + 1);
    a[n + 1] = N;
    fo(i, 1, n)
    {
        memset(f[i & 1], 0, sizeof f[i & 1]);
        fo(j, 1, i) fo(k, 0, l) fo(m, 0, min(2ll, i))
        {
            int delta = (2 * j - m) * (a[i + 1] - a[i]);
            if (k < delta or i + j + 1 - m > n)
                continue;
            add(f[i & 1][j][k][m], f[1 - i % 2][j - 1][k - delta][m]);
            if (m)
            {
                add(f[i & 1][j][k][m], (2 - (m - 1)) * f[1 - i % 2][j - 1][k - delta][m - 1]);
            }
            add(f[i & 1][j][k][m], (2 * j - m) * f[1 - i % 2][j][k - delta][m]);
            if (m == 1)
                add(f[i & 1][j][k][m], 2 * j * f[1 - i % 2][j][k - delta][m - 1]);
            if (m == 2)
            {
                if (i == n)
                    add(f[i & 1][j][k][m], f[1 - i % 2][j][k - delta][m - 1]);
                else if (j > 1)
                    add(f[i & 1][j][k][m], (j - 1) * f[1 - i % 2][j][k - delta][m - 1]);
            }
            if (m == 2)
            {
                if (i == n)
                    add(f[i & 1][j][k][m], f[1 - i % 2][j + 1][k - delta][m]);
                else
                    add(f[i & 1][j][k][m], j * (j - 1) * f[1 - i % 2][j + 1][k - delta][m]);
            }
            else if (m == 1)
                add(f[i & 1][j][k][m], j * j * f[1 - i % 2][j + 1][k - delta][m]);
            else
                add(f[i & 1][j][k][m], j * (j + 1) * f[1 - i % 2][j + 1][k - delta][m]);
        }
    }
    int ans = 0;
    fo(i, 0, l) add(ans, f[n & 1][1][i][2]);
    cout << ans;
}

Compilation message (stderr)

skyscraper.cpp:61:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   61 | main()
      | ^~~~
skyscraper.cpp: In function 'int main()':
skyscraper.cpp:66:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |         freopen(name ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:67:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |         freopen(name ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 80 / 80