C语言用递归算法实现：整数模幂运算 x的r次模p.用循环控制比较简单,但是自己用递归写了个运行时结果不

需要输入x,r,p
#include
void Run(int x,int r,int p,int t)
{
int a,b,c;
a=x;b=r;c=t;
if(b==0)
{
printf("%d",c);
return;
}
if((b>0)&&(b%2==0))
{
b=b/2;
a=(a*a)%p;
}
else
{
b=b-1;
c=(a*c)%p;
}
Run(a,b,p,c);
}
void main()
{
int x,r,p,t=1;
printf("please enter x :");
scanf("%d",&x);
printf("please enter r :");
scanf("%d",&r);
printf("please enter p :");
scanf("%d",&p);
Run(x,r,p,t);
}