如何改成java输出

#include
#include
#include
#include
#include
#include

using namespace std;

int main()
{
string a,b,c;

cin >> a >> b >> c;

int len = a.length();

int res = 0;
for (int i = 0; i < len; ++i) {
    set<int>s;
    s.insert(a[i]);
    s.insert(b[i]);
    s.insert(c[i]);
    if (s.size() == 2) ++res;
    if (s.size() == 3) res += 2;
}

cout << res << endl;

return 0;

Java代码参考如下：

public static void main(String[] args) {
    String a, b, c;
    Scanner sc = new Scanner(System.in);
    a = sc.nextLine();
    b = sc.nextLine();
    c = sc.nextLine();
    int len = a.length();
    int res = 0;
    for (int i = 0; i < len; ++i) {
        Set<String> s = new HashSet<>();
        if (i < a.length()) {
            s.add(a.substring(i, i + 1));
        }
        if (i < b.length()) {
            s.add(b.substring(i, i + 1));
        }
        if (i < c.length()) {
            s.add(c.substring(i, i + 1));
        }
        if (s.size() == 2) ++res;
        if (s.size() == 3) res += 2;
    }
    System.out.println(res);
}