Submission #464345

#	Time	Username	Problem	Language	Result	Execution time	Memory
464345		Kerim	Rack (eJOI19_rack)	C++17	100 / 100	4 ms	4044 KiB

rack

#include "bits/stdc++.h"
#define MAXN 1000009
#define INF 1000000007
#define mp(x,y) make_pair(x,y)
#define all(v) v.begin(),v.end()
#define pb(x) push_back(x)
#define wr cout<<"----------------"<<endl;
#define ppb() pop_back()
#define tr(ii,c) for(__typeof((c).begin()) ii=(c).begin();ii!=(c).end();ii++)
#define ff first
#define ss second
#define my_little_dodge 46
#define debug(x)  cerr<< #x <<" = "<< x<<endl;
using namespace std;
 
typedef long long ll;
typedef pair<int,int> PII;
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
int pw[MAXN],N;
ll K;
int mod(int x){
	if(x>=INF)x-=INF;
	return x;
}
int a(int n,ll k,int res=1){
	while(k)res=mod(res+(k%2)*pw[n--]),k/=2;
	return res;
}
int main(){
    //~ freopen("file.in", "r", stdin);
    scanf("%d%lld",&N,&K);pw[0]=1;
    for(int i=1;i<=N;i++)pw[i]=mod(pw[i-1]+pw[i-1]);
    printf("%d\n",a(N-1,K-1));
	return 0;
}

	
//(a(n, k) = if( k<=0 || k>=n, 0, if( k%2, n\2) + a(n\2, k\2))); 
//{T(n, k) = if( k<=0 || k>2^n/2, 0, 1 + a(2^n/2, k-1))}; 

Compilation message (stderr)

rack.cpp: In function 'int main()':
rack.cpp:32:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |     scanf("%d%lld",&N,&K);pw[0]=1;
      |     ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 60 / 60