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The mid-square method is a method of generating pseudorandom numbers. This method was invented by John von Neumann and was described at a conference in 1949

In this technique, an initial seed value is taken and it is squared.

Some digits from the middle are extracted and these extracted digits form a number which is taken as the new seed.

Let us take 3456 as seed. Its square is 11943936

Take the middle 4 digits as new seed i.e. 9439. Its square is 89094721

Take middle 4 digits as new seed i.e. 0947

Repeat this process

1. Choose initial seed value 2. Take the square of the seed value 3. Update seed by taking n digits from previous result

#include <iostream> #include <ctime> using namespace std; long long getTime(){ time_t t = time(NULL); struct tm *tm = localtime(&t); long long x = (tm->tm_hour) * 50000000 + (tm->tm_min) * 100000 + (tm->tm_sec) * 5000 + (tm->tm_mday) * 50 + (tm->tm_year); return x; } long getHash(){ long long key = getTime(); key = key * key; key = key / 10000; key = key % 100000000; return key; } int main(){ cout << "Random number: " << getHash() << endl; return 0; }

When you compile and execute the above program. It generates the following output−

Random number: 10088419

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