Submission #442847

#	Time	Username	Problem	Language	Result	Execution time	Memory
442847		parsabahrami	Skyscraper (JOI16_skyscraper)	C++17	100 / 100	269 ms	84748 KiB

skyscraper

/* I do it for the glory */
#include <bits/stdc++.h>
 
using namespace std;

typedef long long int ll;
typedef pair<int, int> pii;
 
#define SZ(x)                       (int) x.size()
#define F                           first
#define S                           second

const int N = 1e2 + 10, MOD = 1e9 + 7;
int dp[N][N][10 * N][3], A[N], n, L;

void add(int &x, int y) {
    x += y;
    if (x >= MOD) x -= MOD;
}

int main() {  
    scanf("%d%d", &n, &L);
    dp[0][0][0][0] = 1;
  	if (n < 2) return !printf("1\n");
    for (int i = 1; i <= n; i++) 
        scanf("%d", &A[i]);
    sort(A + 1, A + n + 1);
    for (int i = 1; i <= n; i++) {
        for (int j = 0; j <= n; j++) {
            for (int k = 0; k <= L; k++) {
                for (int t = 0; t <= min(j, 2); t++) {
                    int nk = k + (A[i] - A[i - 1]) * (2 * j - t);
                    if (nk > L) continue;
                    add(dp[i][j + 1][nk][t], 1ll * dp[i - 1][j][k][t] * (j + 1 - t) % MOD);
                    if (t < 2) 
                        add(dp[i][j + 1][nk][t + 1], dp[i - 1][j][k][t] * (2ll - t) % MOD);
                    if (t < 2 && j) 
                        add(dp[i][j][nk][t + 1], dp[i - 1][j][k][t] * (2ll - t) % MOD);
                    if (j > 1) 
                        add(dp[i][j - 1][nk][t], 1ll * dp[i - 1][j][k][t] * (j - 1) % MOD); 
                    if (j) 
                        add(dp[i][j][nk][t], dp[i - 1][j][k][t] * 1ll * (2 * j - t) % MOD);
                }
            }
        }
    }
    int ret = 0;
    for (int i = 0; i <= L; i++) 
        add(ret, dp[n][1][i][2]);
    printf("%d\n", ret);
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:22:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   22 |     scanf("%d%d", &n, &L);
      |     ~~~~~^~~~~~~~~~~~~~~~
skyscraper.cpp:26:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |         scanf("%d", &A[i]);
      |         ~~~~~^~~~~~~~~~~~~

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