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// BiggestUnInt2.cc
// usage:
// BiggestUnInt2 <starting number> (optional argument, default is 1)
// example:
// BiggestUnInt2 4194305
// features:
#include <iostream>
#include <cstdlib>
using namespace std;
void bitsout( unsigned int n );
int main(int argc, char* argv[])
{
int N=0;
unsigned int i=1 , oldi , j ;
if(argc>1) {
sscanf( argv[1], "%u", &i ) ; // starting value
}
cout << "#\ti \ti+(i-1)\t2i\n" ;
cout << "#\t#### \t#######\t###\n" ;
do {
oldi = i ;
j = i-1 ;
j += i ; // this sets j = 2i-1 (we hope)
i *= 2 ; // this doubles i (we hope)
cout << N << ":\t" << oldi << "\t" << j << "\t" << i << "\t";
bitsout(i);
cout << endl ;
N++;
} while ( j+1==i && i!=0 ) ; // keep going until something odd happens
// (Under normal arithmetic,
// we always expect A: j+1 to equal i, and
// we always expect B: i not to be 0
// we keep going while _both_ A _and_ B are true.)
// ( '&&' means "_and_" )
}
void bitsout( unsigned int m )
{
int lastbit ;
unsigned int two_to_power_i ;
for ( int i = 31 ; i >= 0 ; i -- ) {
two_to_power_i = (1<<i) ;
lastbit = ( two_to_power_i & m ) == 0 ? 0 : 1 ;
cout << lastbit ;
}
}
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