>>708 こういう事か？
#include <stdio.h>

int sum(int, int, int *);

int sum(int first, int last, int *array)
{
if(first==last)
return array[first];
else
return array[first] + sum(first + 1, last, array);
}


int main(void){
int a[]={10, 2, 1, 3, 4};

printf("%d\n", sum(0, 4, a) );
return 0;
}