Robin Robotics

 ALGORITHM The problem is to place n queens on an n * n chessboard, so that no two queens are attacking each other.this means that no two queens are in the same row, the same column, or the same diagonal. This is the algorithm for n queens backtracking : PLACEQUEENS(Q[1..N],r):        if r=n+1             print Q[1...n]        else             for j <-- 1 to n                  legal <--- TRUE                  for i <-- 1 to r-1                       if (Q[i]=j) or (Q[i]=j+r-i) or (Q[i] =j-r+i)  :                                  legal <-- FALSE                                    if legal                          Q[r] <-- j                          PLACEQUEENS(Q[1..N],r+1)   //recursion Here represent the positions of the queens using an array Q[1 .. n], where Q[i] indicates which square in row i contains a queen. When backtrack is called, the input parameter r is the index of the first empty row, and the prefix Q[1 .. r 1] contains the positio

INSTALL ROS WITH FEW LINE OF CODE IN UBUNTU let see how to setup ros in ubuntu with few lines of code in here I prefer ubuntu 16.04 & ros kinetic version because you can get all the updated and working packages from ros community Here you can do it by two ways  1.just download ros_ubuntu_install.sh    and make it executable through below command    chmod + x / path / to /ros_ubuntu_install . sh then ./ ros_ubuntu_install . sh Thats it all the things getting complete automatically within 10-15 mints just wait.. check below demo video: 2. otherwise copy each & every commands below and paste it into terminal just copy below commands one by one below & paste it terminal (you should need nice Internet connection it will take some time to complete) sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list' sudo apt-ke

Topics , Its look like pipe line connection between two or more nodes,This is the way to transfer data continuously within two nodes.    Each message in ROS is transported using named buses called topics. When a node sends a message through a topic, then we can say the node is publishing a topic. When a node receives a message through a topic, then we can say that the node is subscribing to a topic. The publishing node and subscribing node are not aware of each other's existence. We can even subscribe a topic that might not have any publisher. In short, the production of information and consumption of it are decoupled. Each topic has a unique name, and any node can access this topic and send data through it as long as  they have the right message type Ros topic have two types of method   1. topic publisher   2. topic subscriber  ROS has a tool to work with topics called rostopic . It is a command-line tool that gives us information about the topic or publishes