Evaluating a Polynomial

You are given a polynomial of degree n. The polynomial is of the form P(x) = anxn + an-1xn-1 + … + a0, where the ai‘s are the coefficients. Given an integer x, write a program that will evaluate P(x).

INPUT: Line 1 contains the integers n and x separated by whitespace.
Line 2 contains the coefficients an, an-1…, a0 separated by whitespace.

OUTPUT: A single integer which is P(x).

CONSTRAINTS: The inputs will satisfy the following properties. It is not necessary to validate the inputs.
1 <= n <= 10 1 <= x <= 10 0 <= ai <=10

#include<stdio.h>

int power(int x, int y);

int main()

{

int n,a[10],i,x,p=0;

scanf("%d%d",&n,&x);

i=n;

while(i>=0)

{

scanf("%d",&a[i]);

i--;

}

for(i=n;i>=0;i--)

{

p += a[i]*power(x,i);

}

printf("%d",p);

return 0;

}

int power(int x, int y)

{

int result = x;

if(y == 0)

return 1;

if(x < 0 || y < 0)

return 0;

for(int i = 1; i < y; ++i)

result *= x;

return result;

}