分治法求一组数据的和

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

int add(int a[] ,int m, int n);

int main(void)
{
  int n;
  printf("please input number n :\n");
  scanf("%d",&n);

  int *a = NULL;
  a = (int *)malloc(sizeof(int)*n);
  printf("please input %d number in a row:\n",n);
  for(int i = 0 ; i < n ; i++)
  {
    scanf("%d",(a+i));
  }
  int m = 0 ;
  int s = add(a , m, n-1);
  
  printf("the sum is %d\n",s);

  return 0;
}

int add(int a[] ,int m, int n)
{
     if(m == n)
	 {
	    return a[m];
	 }
	 else
	 {
	     int ls , rs ;
		 int mid = (m + n)/2;
		 ls = add(a,m, mid);
		 rs = add(a,mid+1, n);
		 return ls+rs;
	 }
 
}#include<stdio.h>
#include<stdlib.h>

int add(i