6-1
#include<stdio.h> int main(void) { int i; char ch_lower,ch_upper; for(i=1;i<=6;i++) { scanf("%c",&ch_lower); if(ch_lower>='a'&&ch_lower<='z') ch_upper=ch_lower-'a'+'A'; printf("%c->%c->%d ",ch_lower,ch_upper,ch_upper%10); } return 0; }
6-2
#include<stdio.h> int main(void) { char ch='w'; int a=2,b=3,c=1,d,x=10; printf("%d",a>b==c); printf("%d",d=a>b); printf("%d",ch>'a'+1); printf("%d",d=a+b>c); printf("%d",b-1==a!=c); printf("%d",3<=x<=5); return 0; }
6-3
#include<stdio.h> int main(void) { char ch='w'; int a=2,b=0,c=0; float x=3.0; printf("%d",a&&b); printf("%d",a||b&&c); printf("%d",!a&&b); printf("%d",a||3+10&&2); printf("%d",!(x==2)); printf("%d",!x==2); printf("%d ",ch||b); return 0; }
6-5
#include<stdio.h> int main(void) { char ch; printf("input characters:"); ch=getchar( ); while(ch!=' '){ if(ch>='A'&&ch<='Z') ch=ch-'A'+'a'; else if(ch>='a'&&ch<='z') ch=ch-'a'+'A'; putchar(ch); ch=getchar( ); } return 0; }