Submission #365428

#	Time	Username	Problem	Language	Result	Execution time	Memory
365428		BartolM	Skyscraper (JOI16_skyscraper)	C++17	20 / 100	938 ms	94700 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;

#define X first
#define Y second
#define mp make_pair
#define pb push_back
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <int, pii> pip;
typedef pair <pii, int> ppi;
typedef pair <ll, ll> pll;

const int INF=0x3f3f3f3f;
const int N=14;
const int MOD=1e9+7;

int n, m;
int p[N];
int dp[(1<<14)+2][N][105];

int add(int a, int b) {
    return (a+b)%MOD;
}

int rek(int mask, int pr, int br) {
    if (br>m) return 0;
    if (__builtin_popcount(mask)==n) return 1;

    int &ret=dp[mask][pr][br];
    if (ret!=-1) return ret;

    ret=0;
    for (int i=0; i<n; ++i) {
        if (mask & (1<<i)) continue;
        ret=add(ret, rek(mask | (1<<i), i, br+abs(p[i]-p[pr])));
    }
    return ret;
}

void solve() {
    sort(p, p+n);
    int sol=0;
    do {
        int res=0;
        for (int i=1; i<n; ++i) res+=abs(p[i]-p[i-1]);
        sol+=res<=m;
    }
    while (next_permutation(p, p+n));
    printf("%d\n", sol);
}

void load() {
    scanf("%d %d", &n, &m);
    for (int i=0; i<n; ++i) scanf("%d", &p[i]);
}

int main() {
    load();
    assert(n<=14);

    if (n<=8) {
        solve();
        return 0;
    }

    memset(dp, -1, sizeof dp);
    int sol=0;
    for (int i=0; i<n; ++i) sol=add(sol, rek((1<<i), i, 0));
    printf("%d\n", sol);
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'void load()':
skyscraper.cpp:55:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   55 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
skyscraper.cpp:56:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   56 |     for (int i=0; i<n; ++i) scanf("%d", &p[i]);
      |                             ~~~~~^~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 0 / 80