mysort函数
谁能解释一下mysort函数里为什么这样写？#include <iostream>
using namespace std;
struct A {
int nouse1;
int nouse2;
int n;
};
void mysort(void *a,int n,int width,int(*f)(const void* e1,const void* e2))
{
for(int i=n-1;i>=0;i--)
{
for(int j=0;j<i;j++)
{
char * aj=(char*)a+j*width;
char * aj1=(char*)a+(j+1)*width;
if(f(aj,aj1)>0)
{
for(int k=0;k<width;k++)
{
char temp=aj;
aj=aj1;
aj1=temp;
}
}
}
}
}
int MyCompare1( const void * e1,const void * e2)
{
int * p1 = (int * ) e1;
int * p2 = (int * ) e2;
return * p1 - * p2;
}
int MyCompare2( const void * e1,const void * e2)
{
int * p1 = (int * ) e1;
int * p2 = (int * ) e2;
if( (* p1 %10) - (* p2 % 10))
return (* p1 %10) - (* p2 % 10);
else
return * p1 - * p2;
}
int MyCompare3( const void * e1,const void * e2)
{
A * p1 = (A*) e1;
A * p2 = (A*) e2;
return p1->n - p2->n;
}
int a;
A b;
int main ()
{
int n;
while(cin >> n) {
for(int i = 0;i < n; ++i) {
cin >> a;
b.n = a;
}
mysort(a,n,sizeof(int),MyCompare1);
for(int i = 0;i < n; ++i)
cout << a << "," ;
cout << endl;
mysort(a,n,sizeof(int),MyCompare2);
for(int i = 0;i < n; ++i)
cout << a << "," ;
cout << endl;
mysort(b,n,sizeof(A),MyCompare3);
for(int i = 0;i < n; ++i)
cout << b.n << "," ;
cout << endl;
}
return 0;
}
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