clarkdo

class Solution {
    public int solution(int[] A) {
        int length = A.length;
        boolean[] appearance = new boolean[length];
        int count = 0;
        for (int i : A) {
            int position = i-1;
            if (i <= length && !appearance[position]) {
                appearance[position] = true;
                count++;

clarkdo

class Solution {
    public int solution(int X, int[] A) {
        int second = -1;
        int count = 0;
        boolean[] counter = new boolean[X];
        for (int i = 0; i < A.length; i++) {
            int pos = A[i];
            if (pos <= A.length && !counter[pos-1]) {
                counter[pos-1] = true;
                count++;

clarkdo

class Solution {
    public int solution(int[] A) {
        int min = A.length + 1;
        int length = A.length;
        boolean[] appearance = new boolean[length];
        for (int i = 0; i < length; i++) {
            if (A[i] > 0 && A[i] <= length) {
                appearance[A[i]-1] = true;
            }
        }

clarkdo

class Solution {
    public int solution(int A, int B, int K) {
        return B/K - (A == 0 ? -1 : (A-1)/K);
    }
}

clarkdo

class Solution {
    public int solution(int[] A) {
        int pairs = 0; 
        int easts = 0;
        for (int i : A) {
            if (i == 0) {
                easts++;    
            } else {
                pairs += easts;
            }

clarkdo

import java.util.Arrays;

class Solution {
    public int solution(int[] A) {
        if (A == null || A.length < 3) return 0;
        int max = Integer.MAX_VALUE;
        Arrays.sort(A);
        long last = A[A.length-1];
        for (int i = 0; i < A.length-2; i++) {
            long P = A[i];

clarkdo

import java.util.Set;
import java.util.HashSet;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(int[] A) {
        Set<Integer> distincts = new HashSet<>();
        for (int i: A) {

clarkdo

import java.util.*;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(int[] A) {
        Arrays.sort(A);

        int length = A.length;

clarkdo

import java.util.List;
import java.util.ArrayList;

class Solution {
    public int solution(String S) {
        if (S == null || S.length() == 0) return 1;
        if (S.length() % 2 != 0) return 0;
        
        char first = S.charAt(0);
        if (first != '{' && first != '[' && first != '(') return 0;

clarkdo

class Solution {
    public int solution(int[] A) {
        int length = A.length;
        
        int leader = A[0];
        int votes = 1;
        
        //Boyer–Moore majority vote algorithm
        for (int i = 1; i < length; i++) {
            int digit = A[i];