adding Codes

Author: sauravjaiswalsj

Leetcode/FindPeakElement.class

@@ -0,0 +1,45 @@
+import java.util.*;
+public class FindPeakElement{
+public static void main(String[] args){
+final Scanner cin=new Scanner(System.in);
+int n=cin.nextInt();
+int[] nums=new int[n];
+for(int i=0;i<n;i++){
+nums[i]=cin.nextInt();
+}
+System.out.println(peakIndex(nums));
+}
+public static int PeakIndex(int[] nums){
+//brute forxece -O(n)
+for(int i=1;i<nums.length;i++){
+if(nums[i]<nums[i-1]){
+return i-1;
+}
+}
+if(nums[nums.length-2]==nums[nums.length-1]){
+return nums.length-2;
+}
+return nums.length-1;
+}
+// 0 1 2 3 4 5
+// 1 2 3 4 1 5 
+// 1 2 3 4 1 5 -> mid =2(3)
+// 3 > 4 and 3 > 2 -> return mid
+// check mid-> mid -1(2) -> left mid+1
+// right => mid -1
+public static int peakIndex(int[] nums){
+int left=0,right=nums.length-1;
+while(left<=right){
+int mid=(left+right)/2;
+if((nums[mid]>nums[mid-1] && mid>0) && (mid<nums.length && nums[mid]>nums[mid+1])){
+return mid;
+}else if(mid-1>=0 && nums[mid]>nums[mid-1]){
+left=mid+1;
+}
+else if(mid+1<nums.length && nums[mid]<nums[mid+1]){
+right=mid-1; 
+}
+}
+return -1;
+}
+}

Leetcode/FindPeakElement.java

@@ -0,0 +1,39 @@
+import java.util.*;
+public class removeDuplicates{
+public static void main(String[] args){
+Scanner cin=new Scanner(System.in);
+int n=cin.nextInt();
+int[] ar=new int[n];
+for(int i=0;i<n;i++){
+ar[i]=cin.nextInt();
+}
+int index=removeTwice(ar);
+for(int i=0;i<index;i++){
+System.out.print(ar[i]+" ");
+}
+}
+private static int remove(int[] ar){
+int left=1;
+for(int right=0;right<ar.length-1;right++){
+//	System.out.println(ar[i]+" "+ar[i+1]);
+if(ar[right]!=ar[right+1]){
+//	System.out.println("c"+ar[i]+" "+ar[i+1]);
+ar[left++]=ar[right+1];
+
+}
+}
+return left;
+}
+public static int removeTwice(int[] ar){
+int left= 2;
+for(int right=2;right<ar.length;right++){
+if((ar[left-2]!=ar[right])){
+ar[left++]=ar[right];
+//	lc=1;
+}
+}
+//System.out.println();
+return left;
+}
+
+}

Leetcode/removeDuplicates.class

@@ -0,0 +1,17 @@
+import java.io.*;
+public class Main{
+public static void main(String[] args)throws IOException{
+final BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
+for(int test=Integer.parseInt(br.readLine());test>0;test--){
+System.out.println(getShortString(br.readLine()));
+}
+}
+private static String getShortString(String s){
+if(s.length()<=10){
+return s;
+}
+int len=s.length()-2;
+String t=s.charAt(0)+String.valueOf(len)+s.charAt(s.length()-1);
+return t;
+}
+}

Leetcode/removeDuplicates.java

@@ -0,0 +1,32 @@
+import java.util.Scanner;
+public class maxPoint{
+public static void main(String[] args){
+Scanner cin=new Scanner(System.in);
+int n=cin.nextInt();
+int[] x=new int[n];
+int[] y=new int[n];
+for(int i=0;i<n;i++){
+x[i]=cin.nextInt();
+}
+for(int i=0;i<n;i++){
+ y[i]=cin.nextInt();
+ }
+System.out.println(maxCount(x,y));
+}
+private static int maxCount(int[] x,int[] y){
+int count=1,newSlope=0;
+int slope=(y[1]-y[0])/(x[1]-x[0]);
+for(int i=1;i<x.length;i++){
+try{
+newSlope=((y[i]-y[0])/(x[i]-x[0]));
+}
+catch(Exception e){
+newSlope=((y[i]-y[1])/(x[i]-x[1]));
+}
+if(newSlope==slope){
+count++;
+}
+}
+return count;
+}
+}

codeforces/Practice/FingerPrint.class

@@ -0,0 +1,84 @@
+import java.util.*;
+class LinkedList{
+private class node{
+int data;
+node next;
+node(){
+data=0;
+next=null;
+}
+node(int item){
+data=item;
+next=null;
+}
+}
+ private node head,tail;
+ private int size=0;
+ public void display(){
+ node temp=this.head;
+ while(temp!=null){
+ System.out.print(temp.data+" ");
+ temp=temp.next; 
+ }
+ System.out.println(" First: "+this.head.data+" last:"+this.tail.data);
+
+ }
+ public void addFirst(int item){
+node temp=new node(item);
+temp.next=this.head;
+this.head=temp;
+if(size==0) this.tail=temp;
+this.size++;
+ }
+ public void addLast(int item){
+ node temp=new node(item);
+ if(this.head == null){
+ this.head=temp;
+ } 
+ else{
+ this.tail.next=temp;
+ } 
+ this.tail=temp;
+ this.size++;
+ temp=null;
+ }
+ public int middleElement(){
+ node temp=this.head;
+ int mid=this.size/2;
+ int i=0,count=-1;
+ while(i<=mid){
+count=temp.data;
+temp=temp.next;
+i++;
+ }
+ return count;
+ }
+ public int FasterMid(){
+ node slow=this.head;
+ node fast=this.head;
+ while(fast.next!=null && fast.next.next!=null){
+ slow=slow.next;
+ fast=fast.next.next;
+ }System.out.println(slow.next);
+ return slow.data;
+ }
+}
+public class Insertion{
+ public static void main(String[] args){
+ LinkedList list=new LinkedList();
+ Scanner cin=new Scanner(System.in);
+ int n=cin.nextInt();
+ for(int i=0;i<n;i++){
+ list.addLast(cin.nextInt());
+ }
+ list.display();
+ System.out.println(list.middleElement());
+ list.addFirst(100);
+ list.addLast(200);
+ list.display();
+ System.out.println("Faster Mid: "+list.FasterMid());
+
+ }
+}
+
+