tozero.c

問題はこちら
http://nabetani.sakura.ne.jp/hena/ord13updowndouble/

# include <stdio.h>
# include <stdlib.h>

int solve(const char * const input)
{
  int i, n = atoi(input);
  for(i=0; n!=0; i++) {
    n = (n%2==0) ? n>>1:
        ((n+1)%4==0 && n!=3) ? n+1: n-1;
  }
  return i;
}

void test(const char * const input, const char * const ans)
{
  const int result = solve(input);
  printf("%d\t%s\n", result, (atoi(ans) == result) ? "OK": "NG");
}

int main()
{
/*0*/ test( "59", "9" );    
/*1*/ test( "10", "5" );    
/*2*/ test( "11", "6" );    
/*3*/ test( "12", "5" );    
/*4*/ test( "13", "6" );    
/*5*/ test( "14", "6" );    
/*6*/ test( "15", "6" );    
/*7*/ test( "16", "5" );    
/*8*/ test( "17", "6" );    
/*9*/ test( "18", "6" );    
/*10*/ test( "27", "8" );    
/*11*/ test( "28", "7" );    
/*12*/ test( "29", "8" );    
/*13*/ test( "30", "7" );    
/*14*/ test( "31", "7" );    
/*15*/ test( "32", "6" );    
/*16*/ test( "33", "7" );    
/*17*/ test( "34", "7" );    
/*18*/ test( "35", "8" );    
/*19*/ test( "41", "8" );    
/*20*/ test( "71", "9" );    
/*21*/ test( "1023", "12" );    
/*22*/ test( "1024", "11" );    
/*23*/ test( "1025", "12" );    
/*24*/ test( "1707", "17" );    
/*25*/ test( "683", "15" );    
/*26*/ test( "123", "10" );    
/*27*/ test( "187", "11" );    
/*28*/ test( "237", "12" );    
/*29*/ test( "5267", "18" );    
/*30*/ test( "6737", "18" );    
/*31*/ test( "14796", "20" );    
/*32*/ test( "18998", "20" );    
/*33*/ test( "23820", "20" );    
/*34*/ test( "30380", "21" );    
/*35*/ test( "31119", "21" );    
/*36*/ test( "33301", "20" );    
/*37*/ test( "33967", "21" );    
/*38*/ test( "35443", "22" );    
/*39*/ test( "35641", "22" );    
/*40*/ test( "43695", "23" );    
/*41*/ test( "44395", "23" );    
/*42*/ test( "44666", "22" );    
/*43*/ test( "987", "14" );    
/*44*/ test( "1021", "13" );    
/*45*/ test( "1019", "13" );    
/*46*/ test( "1015", "13" );    
/*47*/ test( "1007", "13" );    
/*48*/ test( "1011", "14" );    
/*49*/ test( "1003", "14" );    
/*50*/ test( "983", "14" );    
/*51*/ test( "999", "14" );    
/*52*/ test( "2731", "18" );    
/*53*/ test( "6827", "20" );    
/*54*/ test( "10923", "21" );    
/*55*/ test( "27307", "23" );    
/*56*/ test( "43691", "24" );    
/*57*/ test( "109227", "26" );    
/*58*/ test( "174763", "27" );
  return 0;
}