Submission #971222

#	Time	Username	Problem	Language	Result	Execution time	Memory
971222		Beerus13	Skyscraper (JOI16_skyscraper)	C++14	20 / 100	333 ms	487920 KiB

skyscraper

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define bit(mask, i) ((mask >> (i)) & 1)
const int N = 1e2 + 5; 
const int mod = 1e9 + 7;

void add(int &a, int b) {
    a += b;
    if(a >= mod) a -= mod;
    if(a < 0) a += mod;
}

int n, L, a[N];
int dp[1 << 14][14][1005];

void solve() {
    cin >> n >> L;
    for(int i = 0; i < n; ++i) {
        cin >> a[i];
        dp[1 << i][i][0] = 1;
    }
    for(int mask = 1; mask < (1 << n); ++mask) {
        for(int i = 0; i < n; ++i) if(bit(mask, i)) {
            for(int j = 0; j < n; ++j) if(!bit(mask, j)) {
                for(int diff = 0; diff + abs(a[i] - a[j]) <= L; ++diff) {
                    add(dp[mask | (1 << j)][j][diff + abs(a[i] - a[j])], dp[mask][i][diff]);
                }
            }
        }
    }
    int ans = 0;
    for(int i = 0; i < n; ++i) {
        for(int diff = 0; diff <= L; ++diff) add(ans, dp[(1 << n) - 1][i][diff]);
    }
    cout << ans << '\n';
}

signed main() {
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int test = 1;
    // cin >> test;
    while(test--) solve();
    return 0;
}

// https://oj.uz/problem/view/JOI16_skyscraper

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