Submission #310434

#	Time	Username	Problem	Language	Result	Execution time	Memory
310434		VROOM_VARUN	Skyscraper (JOI16_skyscraper)	C++14	100 / 100	337 ms	260728 KiB

skyscraper

/*
ID: varunra2
LANG: C++
TASK: skycraper
*/

#include <bits/stdc++.h>
using namespace std;

#ifdef DEBUG
#include "lib/debug.h"
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define debug_arr(...) \
  cerr << "[" << #__VA_ARGS__ << "]:", debug_arr(__VA_ARGS__)
#pragma GCC diagnostic ignored "-Wsign-compare"
//#pragma GCC diagnostic ignored "-Wunused-parameter"
//#pragma GCC diagnostic ignored "-Wunused-variable"
#else
#define debug(...) 42
#endif

#define EPS 1e-9
#define IN(A, B, C) assert(B <= A && A <= C)
#define INF (int)1e9
#define MEM(a, b) memset(a, (b), sizeof(a))
#define MOD 1000000007
#define MP make_pair
#define PB push_back
#define all(cont) cont.begin(), cont.end()
#define rall(cont) cont.end(), cont.begin()
#define x first
#define y second
#define int long long

const double PI = acos(-1.0);
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef map<int, int> MPII;
typedef multiset<int> MSETI;
typedef set<int> SETI;
typedef set<string> SETS;
typedef vector<int> VI;
typedef vector<PII> VII;
typedef vector<VI> VVI;
typedef vector<string> VS;

#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define trav(a, x) for (auto& a : x)
#define sz(x) (int)(x).size()
typedef pair<int, int> pii;
typedef vector<int> vi;
#pragma GCC diagnostic ignored "-Wsign-compare"
// util functions

// const int N = 105;
// const int L = 1005;

// int dp[N][N][L][3];

// int n, l;
// VI vals;

// void ad(int& a, int b) {
//   b %= MOD;
//   a += b;
//   a %= MOD;
// }

// int solve(int i, int cc, int sum, int bnds) {
//   if (cc == 0 or bnds == 3 or sum > l) return 0;

//   if (i == n) {
//     if (cc == 1 and sum <= l and bnds == 2) return 1;
//     return 0;
//   }

//   if (dp[i][cc][sum][bnds] != -1) return dp[i][cc][sum][bnds];

//   int nsum = sum + (2 * cc - bnds) * (vals[i] - vals[i - 1]);

//   int ret = 0;

//   ad(ret, (cc + 1 - bnds) * solve(i + 1, cc + 1, nsum, bnds));
//   ad(ret, (2 * cc - bnds) * solve(i + 1, cc, nsum, bnds));
//   ad(ret, (cc - 1) * solve(i + 1, cc - 1, nsum, bnds));
//   ad(ret, (2 - bnds) * solve(i + 1, cc + 1, nsum, bnds + 1));
//   ad(ret, (2 - bnds) * solve(i + 1, cc, nsum, bnds + 1));

//   ret %= MOD;

//   dp[i][cc][sum][bnds] = ret;

//   return ret;
// }
const int M = MOD;

const int N = 105;
const int L = 1e3+5;
 
int n, l, vals[N];
long long dp[N][N][L][3];

long long solve(int pos, int cc, int diff, int ends) {
    if(pos == n + 1) return (cc == 1 && diff <= l && ends == 2);
    if(cc == 0 || diff > l || ends == 3) return 0;
    long long &now = dp[pos][cc][diff][ends];
    if(~now) return now;
    
    int ndiff = diff + (vals[pos] - vals[pos - 1]) * (2 * cc - ends);
 
    now = 0;
    now = (now + (cc + 1 - ends) * solve(pos + 1, cc + 1, ndiff, ends) % M) % M;
    now = (now + (2 * cc - ends) * solve(pos + 1, cc, ndiff, ends) % M) % M;
    now = (now + (cc - 1) * solve(pos + 1, cc - 1, ndiff, ends) % M) % M;
    now = (now + (2 - ends) * solve(pos + 1, cc + 1, ndiff, ends + 1) % M) % M;
    now = (now + (2 - ends) * solve(pos + 1, cc, ndiff, ends + 1) % M) % M;
 
    return now;
}

int32_t main() {
  // #ifndef ONLINE_JUDGE
  // freopen("skycraper.in", "r", stdin);
  // freopen("skycraper.out", "w", stdout);
  // #endif
  cin.sync_with_stdio(0);
  cin.tie(0);

  // cin >> n >> l;

  // MEM(dp, -1);

  // vals.resize(n);

  // for (int i = 0; i < n; i++) {
  //   cin >> vals[i];
  // }

  // sort(all(vals));

  // cout << (solve(1, 1, 0, 0) + 2 * solve(1, 1, 0, 1)) % MOD << '\n';

  memset(dp, -1, sizeof dp);
 
    scanf("%d %d", &n, &l);
    for(int i = 1; i <= n; i++) scanf("%d", vals + i);
    sort(vals + 1, vals + n + 1);
 
    if(n == 1) return !printf("1\n");
    printf("%lld\n", (solve(2, 1, 0, 0) + 2 * solve(2, 1, 0, 1)) % M);
 

  return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int32_t main()':
skyscraper.cpp:146:13: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long long int*' [-Wformat=]
  146 |     scanf("%d %d", &n, &l);
      |            ~^      ~~
      |             |      |
      |             int*   long long int*
      |            %lld
skyscraper.cpp:146:16: warning: format '%d' expects argument of type 'int*', but argument 3 has type 'long long int*' [-Wformat=]
  146 |     scanf("%d %d", &n, &l);
      |               ~^       ~~
      |                |       |
      |                int*    long long int*
      |               %lld
skyscraper.cpp:147:41: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long long int*' [-Wformat=]
  147 |     for(int i = 1; i <= n; i++) scanf("%d", vals + i);
      |                                        ~^   ~~~~~~~~
      |                                         |        |
      |                                         int*     long long int*
      |                                        %lld
skyscraper.cpp:146:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  146 |     scanf("%d %d", &n, &l);
      |     ~~~~~^~~~~~~~~~~~~~~~~
skyscraper.cpp:147:38: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  147 |     for(int i = 1; i <= n; i++) scanf("%d", vals + i);
      |                                 ~~~~~^~~~~~~~~~~~~~~~

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