/* t2_2.c ( PASCAL講座 sample program )
for 文、while 文、do - while 文

コンパイル命令は
gcc t2_2.c -o t2_2

実行命令は
t2_2
*/

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define RANDOMIZE()	srand(time(NULL))

main(){
  int a,i,n,x;
  char c,s[64],t[64];
  
  RANDOMIZE();				/* 乱数の初期化 */
  x=0;
  for(i=1;i<=10;i++) x=x+i;
  printf("1 + 2 + ... + 10 = %1d\n",x);
  printf("\n");
  
  strcpy(s,"");
  for(c='a';c<='z';c++) sprintf(s,"%s%c",s,c);
  printf("%s\n",s);
  printf("\n");

  strcpy(s,"");
  for(c='z';c>='a';c--) sprintf(s,"%s%c",s,c);
  printf("%s\n",s);
  printf("\n");
 
  n=rand()%1000+1;
  printf("n = %1d\n",n);
  strcpy(s,"");
  while(n>0){
    a=n%2;
    strcpy(t,s);
    if(a==0) sprintf(s,"0%s",t); else sprintf(s,"1%s",t); 
  printf("%s\n",s);
    n=n/2;
  }
  printf("binary representation = %s\n",s);
  printf("\n");

  n=rand()%1000+1;
  printf("n = %1d\n",n);
  strcpy(s,"");
  do{
    a=n%2;
    strcpy(t,s);
    if(a==0) sprintf(s,"0%s",t); else sprintf(s,"1%s",t); 
    n=n/2;
  }while(n>0);
  printf("binary representation = %s\n",s);
  
}