c语言-关于指针作为参数并改变它的值的问题

#include<stdio.h>
int f(int *p){
    p = p+1;
    return printf("%d\n",*p);
}
void main(){
    int a[]={1,2};
    int *p = a;//指针p是首地址
    f(p);//调用
    printf("%d",*p);//p的值是不会改变的
}

#include<stdio.h>
void z(int *p){
    p = p+1;
    *p = 100;
}
void mian(){
    int a[] = {1,2};
    int *p = a;
    z(p);//调用
    printf("a[1]=%d",*(p+1));//指针（p+1）所指向的内存空间中的值改变了
}

#include<stdio.h>
void exchange(int **x,int **y){
    int *temp;
    temp = *x;//*x=*qq=&a
    *x = *y;
    *y = temp;
}
 
void main(){
    int a =100;
    int b = 12;
//定义指针
    int *q = &a;
    int *p = &b;
    int **qq = &q;
    int **pp = &p;
//输出
    printf("q=%p\n",q);
    printf("p=%p\n",p);
    //调用函数，进行转换
    exchange(qq,pp);
 
    printf("========改变以后的==========\n");
    printf("q=%p\n",q);
    printf("p=%p\n",p);
}