Submission #288544

#	Time	Username	Problem	Language	Result	Execution time	Memory
288544		Benmath	Rack (eJOI19_rack)	C++14	0 / 100	0 ms	256 KiB

rack

#include<bits/stdc++.h>
using namespace std;
long long int solve(long long int step[],long long int b,long long int n,long long int mod){
 
    long long int step1=1;
    long long int x,y;
    long long int b1;
    if(b%2==0){
        y=(b-2)/2;
    }else{
        y=(b-1)/2;
    }
    if(y==0 or b==0){
        return 1;
    }
    int mi=0;
    for(int i=1;i<=n;i++){
        if(i!=1){
            step1*=2;
            mi++;
        }
        if((y-step1)<step1){
            b1=y-step1;
        break;
    }
    }
 b1=b1%mod;
    if(b%2==0){
        return ( solve(step,b1,n-2-mi,mod)*step[n-2-mi]+step[n-1])%mod;
    }else{
        return (solve(step,b1,n-2-mi,mod)*step[n-2-mi])%mod;
    }
}
int main(){
    int n;
    cin>>n;
    long long int k;
    cin>>k;
    long long int mod=1000000007;
    k=k%mod;
    long long int step[n+1];
    step[0]=1;
    for(int i=1;i<=n;i++){
        step[i]=(step[i-1]*2)%mod;
    }
 if(k==1){
     cout<<1;
 }else if(k==2){
     cout<<step[n-1]+1;
 }else{
        cout<<solve(step,k,n,mod)+1;
 }

}

Compilation message (stderr)

rack.cpp: In function 'long long int solve(long long int*, long long int, long long int, long long int)':
rack.cpp:6:19: warning: unused variable 'x' [-Wunused-variable]
    6 |     long long int x,y;
      |                   ^
rack.cpp:27:4: warning: 'b1' may be used uninitialized in this function [-Wmaybe-uninitialized]
   27 |  b1=b1%mod;
      |  ~~^~~~~~~

• Subtask 1: 0 / 20
• Subtask 2: 0 / 20
• Subtask 3: 0 / 60