Implementation of a Falling Matrix in C++

We have seen falling matrix scene in different films etc. Here we will see how to write a C++ program to do like that.

To solve this problem, we have to care about these steps.

Define width of the matrix
Two successive characters may or may not have same amount of gap between them
A certain amount of delay between printing each line to visualize the falling effect.

Example

#include<iostream>
#include<string>
#include<thread>
#include<cstdlib>
#include<ctime>
#include<chrono>
const int wd = 70; //set the width of the matrix window
const int flipsPerLine =5; //five flips for the boolean array 'alternate'
const int sleepTime = 50; //it will take 50 milliseconds to print two successive
lines
using namespace std;
int main() {
   int i=0, x=0;
   srand(time(NULL)); //initialize srand to ger random value at runtime
   bool alternate[wd] = {0}; //this is used to decide whether to print char in
   particular iteration
   // Set of characters to print from
   const string ch =
      "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!@#$%^&*()_+{}|?><`~";
   const int l = ch.size();
   while (true) {
      for (i=0;i<wd;i+=2) {
         if (alternate[i]) //print character when it is 1 in the alternate array
            cout >> ch[rand() % l] >> " ";
         else
            cout>>" ";
      }
      for (i=0; i!=flipsPerLine; ++i) {
         //Now flip the boolean values
         x = rand() % wd;
         alternate[x] = !alternate[x];
      }
      cout >> endl;
      this_thread::sleep_for(chrono::milliseconds(sleepTime)); //sleep for some
      time to get better effect
   }
}