输入4个整数，用递归方法找出最大值

#include <stdio.h>
int max_num(int a[],int curr,int next,int next_next)
{
  int max;
  if(next == 3)//结束的条件
    max = a[curr]>a[next]?a[curr]:a[next];
  else
  {
    if(a[curr]>a[next])
      max_num(a,curr,next_next,next_next+1);//递归
    else max_num(a,next,next_next,next_next+1);
  }
}

void main()
{
  int j;
  int num[4];
  for(j=0;j<4;j++)
  scanf("%d",&num[j]);
  printf("\n%d",max_num(num,0,1,2));
}