Submission #199368

#	Time	Username	Problem	Language	Result	Execution time	Memory
199368		CaroLinda	Skyscraper (JOI16_skyscraper)	C++14	5 / 100	2630 ms	171232 KiB

skyscraper

#include <bits/stdc++.h>

const int MOD = 1e9+7 ;
const int MAXL = 110 ;
const int MAXN = 15 ;

using namespace std ;

int n , l ;
int f[MAXN] ;
long long dp[ (1<<14)+100 ][ MAXL ][ MAXN ] ;

bool isOn(int mask, int i) { return ((1<<i)&mask) != 0 ; } 

long long solve(int mask, int left, int ant)
{
    
    if( dp[mask][left][ant] != -1 ) return dp[mask][left][ant] ;
    if( mask == ( 1<<n )-1 ) return 1 ;
    
    dp[mask][left][ant] = 0 ;
    
    for(int i = 0 ; i < n ; i++ )
        if( !isOn(mask, i) && left >= abs( f[i+1] - f[ant+1] ) )
            dp[mask][left][ant] = ( dp[mask][left][ant] + solve( mask|(1<<i) , left - abs(f[i+1]-f[ant+1]) , i ) ) % MOD ;
    
    return dp[mask][left][ant] ;
    
    
}

int main()
{
    
    scanf("%d%d", &n , &l ) ;
    for(int i = 1 ; i <= n ; i++ ) scanf("%d", &f[i]) ;
    
    if( n <= 8 )
    {
        
        sort( f+1, f+1+n ) ;
        
        int ans = 0 , soma = 0 ;
        
        for(int i = 1 ; i < n ; i++ )
                soma += abs( f[i] - f[i+1] ) ;
        if( soma <= l ) ans ++ ;
        while( next_permutation( f+1, f+1+n ) )
        {
            soma = 0;
            
            for(int i = 1 ; i < n ; i++ )
                soma += abs( f[i] - f[i+1] ) ;
            if( soma <= l ) ans ++ ;
        }
        
        printf("%d\n" , ans ) ;
        return 0 ;
        
    } 
    
    long long ans = 0LL ;
    memset(dp, -1, sizeof dp ) ;
    
    for( int i = 0 ; i < n ; i++  )
        ans = ( ans + solve( (1<<i) , l , i ) ) % MOD ;
    
    printf("%lld\n" , ans ) ;
    
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:35:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &n , &l ) ;
     ~~~~~^~~~~~~~~~~~~~~~~~
skyscraper.cpp:36:41: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(int i = 1 ; i <= n ; i++ ) scanf("%d", &f[i]) ;
                                    ~~~~~^~~~~~~~~~~~~

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