引用与指针

// 写了一个小玩意，复习了一下指针和引用，虽然简单吧，但是还是挺容易错的。
#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>

using namespace std;

int cg(int &a,int &b)
{
    int c;
    c = a;
    a = b;
    b = c;
}

int main()
{
    int a,b;
    scanf("%d%d",&a,&b);
    printf("%d %d\n",a,b);
    // 1 

    int &d = a;
    int &e = b;
    int mid;
    mid = d;
    d = e;
    e = mid;
    printf("%d %d\n",a,b);
    // 2

    cg(a,b);
    printf("%d %d\n",a,b);
    // 3

    int *f = &a;
    int **fl = &f;
    int *g = &b;
    int **gl = &g;
    mid = **fl;
    **fl = **gl;
    **gl = mid;
    printf("%d %d\n",a,b);
    //4

    int *p = &a;
    int *q = &b;
    int *&pl = p;
    int *&ql = q;
    mid = *pl;  
    *pl = *ql;
    *ql = mid;
    printf("%d %d\n",a,b);
    // 5

    int *h = &a;
    int **hl = &h;
    int *k = &b;
    int *&kll = k;
    mid = **hl;
    **hl = *kll;
    *kll = mid;  
    printf("%d %d\n",a,b);
    //6

    return 0;
}