96. Convert Uppercase Letters to Lowercase

#include <stdio.h>
#include <stdint.h>

void to_lowercase(char *str) {
    int buf='a'-'A',len=0;
    while(str[len] != '\0'){
        if(str[len] <= 'Z' && str[len] >= 'A'){
            str[len] = str[len]+buf;
        }
        len++;
    }

}

int main() {
    char str[101];
    fgets(str, sizeof(str), stdin);

    // Remove newline
    uint8_t i = 0;
    while (str[i]) {
        if (str[i] == '\n') {
            str[i] = '\0';
            break;
        }
        i++;
    }

    to_lowercase(str);
    printf("%s", str);
    return 0;
}