Submission #1122224

#	Time	Username	Problem	Language	Result	Execution time	Memory
1122224		gdragon	Skyscraper (JOI16_skyscraper)	C++17	100 / 100	157 ms	77132 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;
#define TASK "long"
#define fi first
#define se second
#define ll long long
#define pb push_back
#define ALL(x) (x).begin(), (x).end()
#define GETBIT(mask, i) ((mask) >> (i) & 1)
#define MASK(i) ((1LL) << (i))
#define SZ(x) ((int)(x).size())
#define mp make_pair
#define CNTBIT(mask) __builtin_popcount(mask)
#define int long long
template<class X, class Y> bool maximize(X &x, Y y){ if (x < y) {x = y; return true;} return false;};
template<class X, class Y> bool minimize(X &x, Y y){ if (x > y) {x = y; return true;} return false;};
typedef pair<int, int> ii;
const int N = 1e2 + 5;
const int M = 1e3 + 2;
const int INF = 1e9 + 7;
const int mod = 1e9 + 7;
void add(int &x, int y) {x += y; if (x >= mod) x -= mod;}
void sub(int &x, int y) {x -= y; if (x < 0) x += mod;}
int mul(int x, int y) {return 1LL * x * y % mod;}
int n, L;
int a[N], dp[N][N][M][3];
void read() {
    cin >> n >> L;
    for(int i = 1; i <= n; i++) cin >> a[i];
}
void solve() {
    if (n == 1) {
        cout << 1;
        return;
    }
    sort(a + 1, a + n + 1);
    dp[0][0][0][0] = 1;
    a[n + 1] = 100000;
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= i; j++) {
            for(int s = 0; s <= L; s++) {
                for(int m = 0; m < 3; m++) {
                    int cost = (a[i + 1] - a[i]) * (2 * j - m);
                    if (cost > s) continue;
                    int &res = dp[i][j][s][m];
                    // cerr << dp[i][j][s][m] << ' ';
                    // join except the end point had fill
                    if (2 * j > m) add(res, mul(dp[i - 1][j][s - cost][m], 2 * j - m));
                    // add end point
                    if (m > 0) add(res, mul(dp[i - 1][j][s - cost][m - 1], 2 - m + 1));
                    // new component with no endpoint
                    if (j > m) add(res, mul(dp[i - 1][j - 1][s - cost][m], j - m));
                    // new component with endpoint
                    if (m > 0) add(res, mul(dp[i - 1][j - 1][s - cost][m - 1], 2 - m + 1));
                    // merge
                    add(res, mul(dp[i - 1][j + 1][s - cost][m], j));
                    // cerr << dp[i][j][s][m] << '\n';
                }
            }
        }
    }
    int ans = 0;
    for(int i = 0; i <= L; i++) add(ans, dp[n][1][i][2]);
    cout << ans;
}
signed main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    if (fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }
    int test = 1;
    // cin >> test;
    while(test--) {
        read();
        solve();
    }
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:69:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:70:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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