TheAlgorithms-C/computer_oriented_statistical_methods/variance.c

#include<stdio.h>
#include <stdlib.h>
#include<math.h>

int main() {

	int *ARRAY=NULL,ARRAY_LENGTH,i,TEMPORARY_ELEMENT,isSorted=0;
	float MEAN=0,VARIANCE=0,STAND;


	printf("Enter no. for Random Numbers :");
	scanf("%d",&ARRAY_LENGTH);
    ARRAY=(int *)realloc(ARRAY,ARRAY_LENGTH*(sizeof(int))); //We allocate the dedicated memory
	for(i=0;i<ARRAY_LENGTH;i++) //We generate the random numbers
		ARRAY[i]=rand()%100;

	printf("Random Numbers Generated are :\n"); //We display them
	for(i=0;i<ARRAY_LENGTH;i++)
		printf("%d ",ARRAY[i]);

	printf("\nSorted Data: ");//Then we sort it using Bubble Sort..

    while(!isSorted){ //While our array's not sorted
        isSorted=1; //we suppose that it's sorted
        for(i=0;i<ARRAY_LENGTH-1;i++){ //then for each element of the array
            if(ARRAY[i]>ARRAY[i+1]){  // if the two elements aren't sorted
                isSorted=0;    //it means that the array is not sorted
                TEMPORARY_ELEMENT=ARRAY[i]; //and we switch these elements using TEMPORARY_ELEMENT
                ARRAY[i]=ARRAY[i+1];
                ARRAY[i+1]=TEMPORARY_ELEMENT;
            }
        }
    }
	for(i=0;i<ARRAY_LENGTH;i++) {
		printf("%d ",ARRAY[i]);
		MEAN=MEAN+ARRAY[i];
	}
	MEAN=MEAN/(float)ARRAY_LENGTH;

	for(i=0;i<ARRAY_LENGTH;i++)
		VARIANCE=VARIANCE+(pow((ARRAY[i]-MEAN),2));

	VARIANCE=VARIANCE/(float)ARRAY_LENGTH;
    STAND=sqrt(VARIANCE);


    printf("\n\n- Mean is: %f\n",MEAN);
	printf("- Variance is: %f\n",VARIANCE);
	printf("- Standard Deviation is: %f\n",STAND);

}