用c语言输出前N个大写字母的有重复全排列，包括重复的也输出

#include <stdio.h>
#include <string.h>

void permutation(char str[], int len, int n) {
static int count = 0;
static int used[26] = {0};
static char result[100] = {0};

if (count == n) {
printf("%s\n", result);
return;
}

for (int i = 0; i < len; i++) {
if (used[i]) {
continue;
}

result[count] = str[i];
used[i] = 1;
count++;

permutation(str, len, n);

count--;
used[i] = 0;
}
}

int main() {
int n;
printf("Enter n: ");
scanf("%d", &n);

char str[26];
for (int i = 0; i < 26; i++) {
str[i] = 'A' + i;
}

int len = strlen(str);
permutation(str, len, n);

return 0;
}