bool is_pangram( const char* str ) {

bool hit_table[128] = { 0, };

int count = 0;


for(int i = 0; str[i]; ++i) {

bool is_lowercase = 'a' <= str[i] && str[i] <= 'z';

char upper_ch = str[i] + is_lowercase * ('A' - 'a');


bool is_letter = 'A' <= upper_ch && upper_ch <= 'Z';

count += is_letter && !hit_table[upper_ch];

hit_table[upper_ch] = 1;

}


return count == 26;

}


으아아