백준 1157번

Python code
alpha = input().lower()
alpha_list = list(set(alpha))
cnt = []
for i in alpha_list:
count = alpha.count(i)
cnt.append(count)
if cnt.count(max(cnt)) >= 2:
print('?')
else:
print(alpha_list[cnt.index(max(cnt))].upper())
C code
#include <stdio.h>
#include <string.h>
int main(){
char alpha[1000001] = {0};
int cnt[26] = {0};
int max = 0;
char max_alpha = '?';
scanf("%s", alpha);
int len = strlen(alpha);
for(int i = 0; i < len; i++){
if(alpha[i] >= 'a'){
cnt[alpha[i] - 'a']++;
}
else{
cnt[alpha[i] - 'A']++;
}
}
for(int i = 0; i < 26; i++){
if(cnt[i] > max){
max = cnt[i];
max_alpha = 'A' + i;
}
else if(cnt[i] == max){
max_alpha = '?';
}
}
printf("%c", max_alpha);
return 0;
}