쉽게 풀어쓴 C언어 EXPRESS(개정 3판) - Chapter 12-2

5.

#include <stdio.h>

#include <string.h>

#include <ctype.h>

int main(void) {

char c;

while(1) {

printf("문자를 입력하시오: ");

c=getchar();

if( islower(c) )

putchar(toupper(c));

if( isupper(c) )

putchar(tolower(c));

if( !isalpha(c) )

printf("경고 ");

if( c=='.') break;

fflush(stdin);

// 줄바꿈 문자 제거

}

return 0;

}

6.

#include <string.h>

#include <stdio.h>

#define SIZE 100

void str_upper(char *s) {

int i;

int count=0;

for (i=0;i<strlen(s);i++) {

if( s[i] >='a' && s[i] <= 'z' )

s[i] = s[i]-'a'+'A';

}

}

int main(void) {

char str[SIZE];

printf("문자열을 입력하시오: ");

gets(str);

str_upper(str);

printf("변환된 문자열: %s\n", str);

return 0;

}

7.

#include <stdio.h>

#include <string.h>

int get_response(char *prompt) {

char response[100];

printf(prompt);

scanf("%s", response);

if( strcmp(response, "yes") == 0 ||

strcmp(response, "y") == 0 ||

strcmp(response, "YES") == 0 ||

strcmp(response, "Y") == 0 )

return 1; else return 0;

}

int main(void) {

int result;

result = get_response("게임을 하시겠습니까");

if( result == 1 )

printf("긍적적인 답변);

else

printf("부정적인 답변);

return 0;

}

8.

#include <string.h>

#include <stdio.h>

char s[] = "Man is immortal, because he has a soul";

char seps[] = " ,\t\n";

char *token;

int main( void ) {

int count=0;

token = strtok( s, seps );

while( token != NULL ) {

count++;

token = strtok( NULL, seps );

}

printf("단어의 수는 %d입니다.\n", count);

return 0;

}