请问如何将字符数组转换回字符串以显示单词。(Caesar cypher)在C语言中

#include <stdio.h>

void convertToString(char arr[], int size) {
    char str[size];
    int i;

    for (i = 0; i < size; i++) {
        str[i] = arr[i];
    }

    printf("Converted string: %s\n", str);
}

int main() {
    char arr[] = {'H', 'e', 'l', 'l', 'o'};
    int size = sizeof(arr) / sizeof(arr[0]);

    convertToString(arr, size);

    return 0;
}