C语言求两个一维数组相乘再求和,求教了

#include <stdio.h>

void main()
{
int a[3]={2,2,2};
int b[3]={1,1,1};
int sum=0;
for(int i=0;i<3;i++)
{
sum+=a[i]*b[i];
}
printf("%d\n",sum);
}

int C[3];
void Fun(int A, int B)
{
for(int i = 0; i < 3; i++)
{
c[i] = a[i] * b[i];
}
}

int x = 0;
for(int i = 0;i < 3;i++)
{
x+=a[i]*b[i];
}

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

int addArrays(int * a, int * b, int n);

main()
{
int n = 0;
int *a, *b;
int x = 0;
int i = 0;
printf("Please input length of the array.\n");
scanf("%d", &n);
fflush(stdin);
a = (int *)malloc(n * sizeof( int ));
b = (int *)malloc(n * sizeof( int ));
printf("Please input %d numbers into array a\n", n);