GREEDY_max activity selection.c

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/*TIME COMPLEXITY
MAXIMUM ACTIVITY SELECTION PROBLEM (GREEDY METHOD)*/

#include<stdio.h>
#include<time.h>
int main()
{
	int n,i,j,temp1,temp2,temp3,lastindex;
	clock_t s,end;
	float t;
	printf("Enter the number of activities to be performed: ");
	scanf("%d",&n);
	int anum[n],start[n],final[n];
	for(i=0;i<n;i++)
	{
		printf("Enter the Activity number, start time and final time for %d process\n",i+1);
		scanf("%d",&anum[i]);
		scanf("%d",&start[i]);
		scanf("%d",&final[i]);
	}
	s=clock();
	for(i=0;i<n-1;i++)						//To perform swapping on the basis of time
	{
		for(j=i+1;j<n;j++)
		{
			if(final[j]<final[i])
			{
				temp1 = final[i];			//swapping done by temporary variable
				final[i] = final[j];
				final[j] = temp1;
				temp2= anum[i];				//swapping done by temporary variable
				anum[i]=anum[j];
				anum[j]=temp2;
				temp3=start[i];				//swapping done by temporary variable
				start[i]=start[j];
				start[j]=temp3;
			}
		}
	}
	printf("Activities sorted by final time are:\n");
	printf("Activity\tStart\tfinish");
	for(i=0;i<n;i++)						//to sort the activities in tabular form
	{
		printf("%d\t%d\t%d\n",anum[i],start[i],final[i]);
	}
	printf("%d Activity is performed\n",anum[0]);
	lastindex=0;
	for(i=1;i<n;i++)						//To sort the activities to get max activity
	{
		if(start[i]>=final[lastindex])
		{	
			printf("%d Activity is performed\n",anum[i]);
			lastindex=i;
		}
	}
	end=clock();
	t=(float)(end-s)/CLOCKS_PER_SEC;
	printf("Time taken for processing is: %f\n",t);
	return 0;
}

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