回文序列问题

bool canPermutePalindrome(char* s) {
    int len = strlen(s);
    int max = s[0];
    int min = s[0];
    // write code here
    for (int i = 0; s[i] != '\0'; i++) {
        if (max <= s[i]) {
            max = s[i];
        }
        if (min >= s[i]) {
            min = s[i];
        }
    }
    int* p = (int*)calloc(max - min + 1, sizeof(int));
    for (int i = 0; s[i] != '\0'; i++) {
        p[s[i] - min]++;
    }
    int odd = 0;
    int even = 0;
    for (int i = 0; i < max - min + 1; i++) {

        if (p[i] % 2 != 0) {
            odd++;
        }
    }
    if (odd <= 1) {
        return true;
    }
    else {
        return false;
    }
}