我是C的新手，试图做一个变位查找器，但它不能正确工作，我不知道我错在哪里。它的工作原理是使用两个独立的整数数组counter1和counter2计算两个不同字符串中的字母数。然后，它应该比较每个计数器中的值并检查任何不匹配，但由于某种原因，它打印了两种可能的结果，而不是正确的结果。任何帮助赞赏！

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

int main(){

  //Letter counter for each string
  int counter1[] = {0, 0, 0, 0};
  int counter2[] = {0, 0, 0, 0};

  // Strings to be checked
  char s1[] = "abcd";
  char s2[] = "dcba";

  //Checks letter count in string 1
  
  for (int i = 0; i < strlen(s1); i++) {
    if (s1[i] == ' ') {
      continue; }
    
    else if (s1[i] == 'a') {
      counter1[0] += 1; }

    else if (s1[i] == 'b') {
      counter1[1] += 1; }

    else if (s1[i] == 'c') {
      counter1[2] += 1; }

    else (s1[i] == 'd'); {
     counter1[3] += 1; }
    
  }

  // Checks letter count in string 2

   for (int i = 0; i < strlen(s2); i++) {
    if (s2[i] == ' ') {
      continue; }
    
    else if (s2[i] == 'a') {
      counter2[0] += 1; }

    else if (s2[i] == 'b') {
      counter2[1] += 1; }

    else if (s2[i] == 'c') {
      counter2[2] += 1; }

    else (s2[i] == 'd'); {
      counter2[3] += 1; }
    
  }

  //Checks for mismatches in the letter counters 

  int flag = 0;
  int counterLen = sizeof(counter1)/sizeof(int);

  for (int i = 0; i < counterLen; i++ ) {
   if (counter1[i] != counter2[i]) {
     flag++; }

  }
    
  //Tells user if it's an anagram or not

  if (flag == 0) {
    printf("Anagram!"); }

  else (flag != 0); {
    printf("Not Anagram!"); }

}