Submission #439587

#	Time	Username	Problem	Language	Result	Execution time	Memory
439587		LucaIlie	Rack (eJOI19_rack)	C11	40 / 100	1 ms	284 KiB

rack

#include <stdio.h>

#define MOD 1000000007

int main() {
    int n, r, p2, e, i;
    long long k;

    scanf( "%d%lld", &n, &k );
    k--;

    p2 = 1;
    e = 0;
    r = 0;
    for ( i = n - 1; i >= 0; i-- ) {
        if ( ((k >> i) & 1) == 1 ) {
            while ( e < (n - 1 - i) ) {
                p2 = (p2 * 2) % MOD;
                e++;
            }
            r = (r + p2) % MOD;
        }
    }

    printf( "%d", r + 1 );

    return 0;
}

Compilation message (stderr)

rack.c: In function 'main':
rack.c:9:5: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 |     scanf( "%d%lld", &n, &k );
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~

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