/* Problem 1

 

Write a function double sumValue (int n) that calculates the following sum: 1/1+1/2+1/3+1/4+…+1/n. 

 

In case and n is negative or zero, the function returns 0.

 

For example:

For n = 1, the function returns 1/1 = 1

For n = 2, the function returns 1/1 +1/2 = 1.5

For n = 3, the function returns 1 +1/2 + 1/3 = 1.833333, and etc.

 

Write a C program that first randomly generates the size of the array, 
an integer between 10 and 20. 
Then, the program generates an array of integers in range -1 to 10. The program prints an array.

Then, for each element of the array, the program uses function 
sumValue to find and print the corresponding sum.

 */


#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#define SIZE 20

//function prototypes
void make_random_array(int A[], int size, int min, int max);
void print_array(int A[], int size);
double sumValue(int);

int main(){
	srand(time(NULL));
	int i, A[SIZE], size=10+rand()%(20-10+1);
	double result;
	make_random_array(A,size, -1,10);
	print_array(A, size);
	for(i=0;i<size;i++){
		result=sumValue(A[i]);
		if(result!=0)
			printf("result is %f\n",result);
		else
			printf("invalid value\n");
	}
	return 0;

}

void make_random_array(int A[], int size, int min, int max){
	int i;
	for(i=0;i<size;i++){
		A[i]=min+rand()%(max-min+1);
	}
}
void print_array(int A[], int size){
	int i;
        for(i=0;i<size;i++){
		printf("%d ",A[i]);
	}
	printf("\n");
}

double sumValue(int n){
	double sum=0.0, i;
	if(n<=0)
		return 0;
	for(i=1;i<=n;i++){
		sum+=1.0/i;
	}
	return sum;
}