打印一个不重复字符串数组的所有组合

// 打印一个字符串数组的所有组合，数组中字符串不重复
// 打印包含n个字符的排序
int print_all_str_combin(char array[], char a[], int n) {
    if (a == nullptr || n < 0) {
        return 0;
    }

    if (n == 0) {
        cout << array << endl;
    } else {
        for (int i = 0; i < n; i++) {
            swap(a[0], a[i]);
            print_all_str_combin(a + 1, n - 1);
            swap(a[i], a[0]);
        }
    }

    return 0;
}

// 打印包含n个字符的排序
int print_all_str_combin(char a[], int n) {
    if (a == nullptr || n < 0) {
        return 0;
    }

    if (n == 0) {
        cout << a << endl;
    } else {
        for (int i = 0; i < n; i++) {
            swap(a[n - 1], a[i]);
            print_all_str_combin(a, n - 1);
            swap(a[n - 1], a[i]);
        }
    }

    return 0;
}

// 打印包含n个字符的排序
int print_all_str_combin(char a[], char* begain) {
    if (a == nullptr || begain == nullptr) {
        return 0;
    }

    if (*begain == '\0') {
        cout << a << endl;
    } else {
        for (char *p = begain; *p != '\0'; p++) {
            swap(begain, p);
            print_all_str_combin(a, begain + 1);
            swap(begain, p);
        }
    }

    return 0;
}