paging.c

#include<stdio.h>
#include<math.h>
void main(){
	int memory_size,page_size;
	printf("Enter Memory Size:");
	scanf("%d",&memory_size);
	printf("Enter Page Size:");
	scanf("%d",&page_size);
	int n=memory_size/page_size;
	printf("No.of Pages available=%d\n",n);
	
	int m[n],i,j;
	for(i=0;i<n;i++){
		m[i]=0;
	}
	
	int p;
	printf("\nEnter No.of Processes:");
	scanf("%d",&p);
	int rem_pages=n;
	int req_pages,process_size;
	
	for(i=0;i<p;i++){
		printf("Enter Process %d size:",i+1);
		scanf("%d",&process_size);
		req_pages=(process_size/page_size);
		if(process_size%page_size!=0) req_pages++;
		if(req_pages>rem_pages){
			printf("Memory is lower than asked");
			continue;
		}
		int temp[req_pages];
		printf("Enter %d page numbers that are to be assigned to process %d:",req_pages,i+1);
		for(j=0;j<req_pages;j++){
			scanf("%d",&temp[j]);
		}
		for(j=0;j<req_pages;j++){
			if(m[temp[j]]!=0){
				printf("Page %d is already allocated",temp[j]);
				break;
			}
			m[temp[j]]=i+1;
			rem_pages--;
		}
	}
	
	printf("Main Memory:\n");
	printf("------------\n");
	for(i=0;i<n;i++){
		if(m[i]==0)
			printf("\tframe %d -- EMPTY\n",i);
		else	
			printf("\tframe %d -- process %d\n",i,m[i]);
	}
}