Question

Write a simple C++ program which will identify how many collisions occur for each of the numbers from 200 thru 600, incremented by 5, when mapping to a hash table array of 100 entries.

Do this by creating a variable and looping to force it to have all values: 200, 205, 210… 600.

First use 100 as the divisor and use the modulo function to do mapping. Then use 101 as the divisor with the modulo function to do the mapping.

Separately, set up an array of 100 entries, whose values will be a count of the number of times its index is created. Initialize to zero.

For example: 200 maps to index value ‘i’ = 99. Add 1 to Array[99].

Output the 101 results to see how the distribution would occur.

Answer 1

Code:-

#include<iostream>
#include<bits/stdc++.h>
using namespace std;

int main(){
   int num=200;
   int hash[100]={0};
int divisor1=100;
int divisor2=101;
   for(num=200;num<=600;num=num+5){
       hash[num%divisor1]++;
       hash[num%divisor2]++;

   }

   for(int i=0;i<100;i++){
       cout<<"index "<<i<<":"<<hash[i]<<endl;
   }
   return 0;
}

First create a array of 100 elements and initialise to 0.Lets two divisors be divisor1=100 and divisor2=101 and iterate from 200 to 600 by incrementing by 5 ,increase the count of hash array i.e for storing how many time it had mapped.

output of code:-