07/07/16 02:23:11
>>15
②
#include<stdio.h>
int toatoi(char *str)
{
int num = 0, sign = 1;
if( *str=='+' ){
str++;
}else if( *str=='-' ){
str++;
sign = -1;
}
do{
if( *str<'0' || '9'<*str )
return -1;
num *= 10; num += *str++ - '0';
}while( *str!='\0' && *str!='\n' );
return sign * num;
}
int main(void)
{
char line[100];
printf(" Input: ");
fgets( line, sizeof(line), stdin);
printf(" 数値: %d\n", toatoi(line));
return 0;
}