From 3f074f0d3c4bfcddbfbe1d8ceabc3db02d00e5c5 Mon Sep 17 00:00:00 2001
From: sushil-sth <45484910+sushil-sth@users.noreply.github.com>
Date: Thu, 24 Oct 2019 07:35:18 +0545
Subject: [PATCH 1/4] skip some of the array elements using C++ program

We are using % (modulus operator) to check every 3rd iteration. If it is, the continue will skip everything down in loop's scope and continue executing the next iteration. For all other elements it will print them.
---
 SkipSomeArray | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 SkipSomeArray

diff --git a/SkipSomeArray b/SkipSomeArray
new file mode 100644
index 0000000..9f05800
--- /dev/null
+++ b/SkipSomeArray
@@ -0,0 +1,17 @@
+#include <iostream>
+using namespace std;
+
+int main()
+{
+	int arr[10] = {1,2,3,4,5,6,7,8,9,10};
+	int i;
+	
+	for(int i=0; i<10; i++)
+	{
+	  if((i+1)%3 == 0)  //If index is every third element
+		continue;  //Continue
+	  cout<<arr[i]<<" ";  //Print array element
+	}
+	
+	return 0;
+}

From 8a1b36d1a09d4ad1c818593ad2793e4d0f44e2e6 Mon Sep 17 00:00:00 2001
From: sushil-sth <45484910+sushil-sth@users.noreply.github.com>
Date: Thu, 24 Oct 2019 07:38:48 +0545
Subject: [PATCH 2/4] Shortest Source to Destination Path

In this article, we are going to see how to find the shortest path from source to destination in a 2D maze.

Given a Boolean 2D matrix (0-based index), find whether there is a path from (0,0) to (x,y) and if there is one path, print the minimum no of steps needed to reach it, else print -1 if the destination is not reachable. Moves are possible in only four directions i.e. up, down, left and right. The path can only be created out of a cell if its value is 1.
---
 ShortestPath | 122 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 122 insertions(+)
 create mode 100644 ShortestPath

diff --git a/ShortestPath b/ShortestPath
new file mode 100644
index 0000000..1bf56ba
--- /dev/null
+++ b/ShortestPath
@@ -0,0 +1,122 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+//checking valid node
+int isvalid(int nextx,int nexty,int m,int n){
+	if(nextx>=0 && nextx<m && nexty>=0 && nexty<n)
+		return 1;
+	return 0;
+}
+
+//defining point
+class point{
+	public:
+	int row;
+	int col;
+	//make point 
+	void mpoint(int m,int n){
+		row=m;
+		col=n;
+	} 
+};
+
+//defining node
+class node{
+	public:
+	point p;
+	int d;
+	void mnode(point q,int dis){ //make node
+		p.row=q.row;
+		p.col=q.col;
+		d=dis;
+	}
+};
+
+
+//finding shortest path
+int shortest(int** a,int m,int n,int x1,int y1){
+	if(a[0][0]==0)//base case
+		return -1;
+
+	bool visited[m][n];
+	//initialize
+	memset(visited,false,sizeof(visited));
+
+	//declare queue by STL 
+	queue<node> q;
+
+	point curr;
+	//set the source point (0,0)
+	curr.mpoint(0,0);
+
+	node t;
+	//set the source node at point (0,0)
+	t.mnode(curr,0); 
+
+	//ENQUEUE source node
+	q.push(t); 
+
+	//direction matrices
+	int arrx[]={-1,0,1,0};
+	int arry[]={0,1,0,-1};
+
+	point c;
+	node v;
+	while(!q.empty()){
+		//DEQUEUE
+		v=q.front();
+
+		c=v.p;
+		//if destnation node is reached
+		if(x1==c.row && y1==c.col ){ 
+			return v.d;
+		}
+		q.pop();
+		//check for all four neighbours
+		for(int i=0;i<4;i++){ 
+			int nextx=c.row+arrx[i];
+			int nexty=c.col+arry[i];
+			//if valid node && not visited yet
+			if(isvalid(nextx,nexty,m,n) && a[nextx][nexty] && !visited[nextx][nexty]){
+				curr.mpoint(nextx,nexty);
+				//set neighbour node by incrementing distance value
+				t.mnode(curr,(v.d)+1); 
+				q.push(t); //EnQueue
+				//mark as visited
+				visited[nextx][nexty]=true;
+			}
+		}
+	}
+	return -1;
+}
+
+
+int main()
+{
+	int m,n,x,y;
+
+	cout<<"enter matrix row & column"<<endl;
+	scanf("%d %d",&m,&n);
+	
+	int **a=(int**)malloc(sizeof(int*)*m);
+	
+	for(int i=0;i<m;i++)
+		a[i]=(int*)(malloc(sizeof(int)*n));
+	
+	cout<<"enter matrix elements (0/1)"<<endl;
+	for(int i=0;i<m;i++)
+		for(int j=0;j<n;j++)
+		scanf("%d",&a[i][j]);
+	
+	cout<<"enter row & column of destinanation point"<<endl;
+	scanf("%d %d",&x,&y);
+	
+	if(shortest(a,m,n,x,y)!=-1)//if path found
+		printf("shortest distance is %d\n",shortest(a,m,n,x,y));
+	else{
+		cout<<-1<<endl;
+		cout<<"no path found\n";
+	}
+	
+	return 0;
+}

From 920348b157e90854f08d4c7df8ef61bc484c6cf7 Mon Sep 17 00:00:00 2001
From: sushil-sth <45484910+sushil-sth@users.noreply.github.com>
Date: Thu, 24 Oct 2019 07:41:46 +0545
Subject: [PATCH 3/4] Change case of a character using bit manipulation in C++

Here, we will learn how to change case of a character using bit manipulation in C++? Program will demonstrate lowercase to uppercase and uppercase to lowercase conversion.
---
 ChangeCharacterCase | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 ChangeCharacterCase

diff --git a/ChangeCharacterCase b/ChangeCharacterCase
new file mode 100644
index 0000000..addedc0
--- /dev/null
+++ b/ChangeCharacterCase
@@ -0,0 +1,28 @@
+#include <iostream>
+using namespace std;
+
+
+char lowerToUpper(char c)
+{
+	return (c & '_');
+}
+
+char upperToLower(char c)
+{
+	// ASCII value of space (' ') is 32 
+	// so it is equivalent to (1 << 5 )
+	return (c | ' ');
+}
+
+int main()
+{
+	char c;
+	cout << "Enter Character ( in lower case ) : \n";
+	cin >> c;
+	cout << "Output :  "  << lowerToUpper(c);
+	cout << "\n\nEnter Character ( in Upper case ) : \n";
+	cin >> c;
+	cout << "Output :  "  << upperToLower(c);
+
+	return 0;
+}

From c275ac25de4b569e63924d5da0fb47afa97d22eb Mon Sep 17 00:00:00 2001
From: sushil-sth <45484910+sushil-sth@users.noreply.github.com>
Date: Thu, 24 Oct 2019 07:45:29 +0545
Subject: [PATCH 4/4] Relative sorting algorithm

we are going to learn relative sorting along with its algorithm, C++ program.

Problem Statement:

Given two array A and B, sort A in such a way that the relative order among the elements will be the same as those in B. For the elements not present in B, append them at last in sorted order. It is also given that the number of elements in B is smaller than or equal to the number of elements in A and B has all distinct elements.
---
 RealtiveSorting | 59 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 RealtiveSorting

diff --git a/RealtiveSorting b/RealtiveSorting
new file mode 100644
index 0000000..da9a1f2
--- /dev/null
+++ b/RealtiveSorting
@@ -0,0 +1,59 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+vector<int> sorted(vector<int> a,vector<int> b,int n1,int n2){
+	vector <int> c;
+	// array a is sorted using labrary sorting function
+	sort(a.begin(),a.end()); 
+
+	for(int i=0;i<n2;i++){
+		for(int j=0;j<n1 && a[j]<=b[i];j++){
+			// elements of sorted a is entered to array c 
+			// maintaing the element order as in b
+			if(a[j]==b[i]){
+				c.push_back(a[j]);
+				//clear the element pushed into c
+				a[j]=0;
+			}
+		}
+	}
+
+	// the elements that are not in b is in being entered to c 
+	// in sorted manner as a is already sorted
+	for(int i=0;i<n1;i++)  
+		if(a[i]!=0)    //remaining elements of a
+			c.push_back(a[i]);
+			
+	//return the output
+	return c; 
+}
+
+
+int main() {
+	int n1,n2,u;
+	vector<int> :: iterator p; //iterator p
+
+	scanf("%d %d",&n1,&n2);
+
+	vector<int> a; //array a
+	vector<int> b;//array b
+
+	for(int j=0;j<n1;j++){
+		scanf("%d",&u);
+		// inputing elements of array a
+		a.push_back(u); 
+	}
+	for(int j=0;j<n2;j++){
+		scanf("%d",&u);
+		// inputing elements of array b
+		b.push_back(u);  
+	}
+
+	// implemented relative sorting function
+	vector<int> c=sorted(a,b,n1,n2); 
+	for(p=c.begin();p!=c.end();p++)	
+		printf("%d ",*p);  // printing the sorted array
+	printf("\n");
+
+	return 0;
+}