Program for Worst Fit algorithm in Memory Management || dot clu

Program for Worst Fit algorithm in Memory Management

Worst Fit allocates a process to the partition which is largest sufficient among the freely available partitions available in the main memory. If a large process comes at a later stage, then memory will not have space to accommodate it.

Suggestion:

1.First Fit
2. Best Fit
3. Worst Fit

Example:

Input : blockSize[]   = {100, 500, 200, 300, 600};
        processSize[] = {212, 417, 112, 426};
Output:
Process No. Process Size Block no.
   1  212  5
   2  417  2
   3  112  5
   4  426  Not Allocated

Implementation:
1- Input memory blocks and processes with sizes.
2- Initialize all memory blocks as free.
3- Start by picking each process and find the
   minimum block size that can be assigned to
   current process i.e., find min(bockSize[1], 
   blockSize[2],.....blockSize[n]) > 
   processSize[current], if found then assign 
   it to the current process.
5- If not then leave that process and keep checking
   the further processes.

Source Code:


#include <iostream>
  
using namespace std;
  
int main()
{
    int nBlocks,nProcess,blockSize[20],processSize[20];
      
    cout<<" Enter the number of blocks: "; cin>>nBlocks;
    cout<<" Enter the number of processes: "; cin>>nProcess;
      
    cout<<" Enter the size of "<<nBlocks<<" blocks: ";
    for(int i=0;i<nBlocks;i++) cin>>blockSize[i];
        
    cout<<" Enter the size of "<<nProcess<<" processes: ";
    for(int i=0;i<nProcess;i++) cin>>processSize[i];
      
 
       
      for(int i=0;i<nProcess;i++)
       {
           int max = blockSize[0];
           int pos = 0;
            
           for(int j=0;j<nBlocks;j++)
            if(max < blockSize[j]) { max = blockSize[j]; pos = j; } if(max >= processSize[i])
            {
                cout<<"\nProcess "<<i+1<<" is allocated to block "<<pos+1;
                blockSize[pos] = blockSize[pos]-processSize[i];
            }
            else{
            cout<<"\nProcess "<<i+1<<" can't be allocated";
                 
            }
       }
 
    return 0;
}