A binary gap within a positive integer N is any maximal sequence of consecutive zeros that is surrounded by ones at both ends in the binary representation of N.
For example, number 9 has binary representation 1001 and contains a binary gap of length 2. The number 529 has binary representation 1000010001 and contains two binary gaps: one of length 4 and one of length 3. The number 20 has binary representation 10100 and contains one binary gap of length 1. The number 15 has binary representation 1111 and has no binary gaps. The number 32 has binary representation 100000 and has no binary gaps.
Write a function:
int solution(int N);
that, given a positive integer N, returns the length of its longest binary gap. The function should return 0 if N doesn't contain a binary gap.
For example, given N = 1041 the function should return 5, because N has binary representation 10000010001 and so its longest binary gap is of length 5. Given N = 32 the function should return 0, because N has binary representation '100000' and thus no binary gaps.
Write an efficient algorithm for the following assumptions:
- N is an integer within the range [1..2,147,483,647].
#include <stdio.h>
# define VALTEST 529
int nMayor(int number)
{
int aux=1, iter =0;
while(aux < number){
iter++;
aux = aux << 1;
//printf("\n%d, %d",iter, aux);
}
return iter;
}
int solucion(int number)
{
int band = 0;
int max0 = 0;
int bVal;
int count;
int bLenght = nMayor(number);
//printf("\n%d\n", bLenght);
while(bLenght--){
bVal = number & 3;
// printf("\n%d, %d, ", number, bVal);
if(bVal == 1){
//printf("c1, ");
band =1;
count = 0;
}
if((bVal==0 || bVal == 2) && band){
//printf("c0, ");
count++;
}
if(bVal == 2){
//printf("c10, ");
if(count > max0){
max0 = count;
//printf("max0= %d, ", max0);
}
band = 0;
}
number = number >> 1;
//printf("count= %d, ", count);
}
return max0;
}
main.o: In function `main': /tmp/user.c:87: undefined reference to `solution' collect2: error: ld returned 1 exit status
#include <stdio.h>
# define VALTEST 529
int nMayor(int number)
{
int aux=1, iter =0;
while(aux < number){
iter++;
aux = aux << 1;
//printf("\n%d, %d",iter, aux);
}
return iter;
}
int solution(int number)
{
int band = 0;
int max0 = 0;
int bVal;
int count;
int bLenght = nMayor(number);
//printf("\n%d\n", bLenght);
while(bLenght--){
bVal = number & 3;
// printf("\n%d, %d, ", number, bVal);
if(bVal == 1){
//printf("c1, ");
band =1;
count = 0;
}
if((bVal==0 || bVal == 2) && band){
//printf("c0, ");
count++;
}
if(bVal == 2){
//printf("c10, ");
if(count > max0){
max0 = count;
//printf("max0= %d, ", max0);
}
band = 0;
}
number = number >> 1;
//printf("count= %d, ", count);
}
return max0;
}
#include <stdio.h>
# define VALTEST 529
int nMayor(int number)
{
int aux=1, iter =0;
while(aux < number){
iter++;
aux = aux << 1;
//printf("\n%d, %d",iter, aux);
}
return iter;
}
int solution(int number)
{
int band = 0;
int max0 = 0;
int bVal;
int count;
int bLenght = nMayor(number);
//printf("\n%d\n", bLenght);
while(bLenght--){
bVal = number & 3;
// printf("\n%d, %d, ", number, bVal);
if(bVal == 1){
//printf("c1, ");
band =1;
count = 0;
}
if((bVal==0 || bVal == 2) && band){
//printf("c0, ");
count++;
}
if(bVal == 2){
//printf("c10, ");
if(count > max0){
max0 = count;
//printf("max0= %d, ", max0);
}
band = 0;
}
number = number >> 1;
//printf("count= %d, ", count);
}
return max0;
}
#include <stdio.h>
# define VALTEST 529
int nMayor(int number)
{
int aux=1, iter =0;
while(aux < number){
iter++;
aux = aux << 1;
//printf("\n%d, %d",iter, aux);
}
return iter;
}
int solution(int number)
{
int band = 0;
int max0 = 0;
int bVal;
int count;
int bLenght = nMayor(number);
//printf("\n%d\n", bLenght);
while(bLenght--){
bVal = number & 3;
// printf("\n%d, %d, ", number, bVal);
if(bVal == 1){
//printf("c1, ");
band =1;
count = 0;
}
if((bVal==0 || bVal == 2) && band){
//printf("c0, ");
count++;
}
if(bVal == 2){
//printf("c10, ");
if(count > max0){
max0 = count;
//printf("max0= %d, ", max0);
}
band = 0;
}
number = number >> 1;
//printf("count= %d, ", count);
}
return max0;
}
The following issues have been detected: wrong answers, timeout errors.
For example, for the input 16 the solution returned a wrong answer (got 1769572280 expected 0).
n=1, n=5=101_2 and n=2147483647=2**31-1
running time: >11.00 sec., time limit: 8.00 sec.
n=1376796946=1010010000100000100000100010010_2
running time: >11.00 sec., time limit: 8.00 sec.
n=1073741825=1000000000000000000000000000001_2
running time: >11.00 sec., time limit: 8.00 sec.
n=1610612737=1100000000000000000000000000001_2
running time: >11.00 sec., time limit: 8.00 sec.