POJ 3270 Cow Sorting

#include <stdio.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#define clear(A, X, SIZE) memset(A, X, sizeof(A[0]) * (SIZE))
#define clearall(A, X) memset(A, X, sizeof(A))
#define max( x, y )  ( ((x) > (y)) ? (x) : (y) )
#define min( x, y )  ( ((x) < (y)) ? (x) : (y) )

using namespace std;
struct node
{
int num,po1,po2;
} x[10005];
bool cmp(const node a,const node b)
{
return a.num<b.num;
}
bool cmp1(const node a,const node b)
{
return a.po1<b.po1;
}
int num[10005],po[10005];
bool vis[10005];
int main()
{
int n,minnum,min2,minp,cost1,cost2,ans,tp;
while(scanf("%d",&n)!=EOF)
{
ans=0;
minnum=1<<30;
for(int i=0; i<n; i++)
{
scanf("%d",&num[i]);
x[i].num=num[i];
x[i].po1=i;
minnum=min(minnum,num[i]);
}
sort(x,x+n,cmp);
for(int i=0; i<n; i++)
{
x[i].po2=i;
po[i]=x[i].po1;
}
sort(x,x+n,cmp1);
clearall(vis,false);
int cnt=n,p;
bool flat;
for(int i=0; i<n&&cnt; i++)
{
if(!vis[i])
{
vis[i]=true;
p=x[i].po2;
min2=x[i].num;
minp=i;
while(p!=i)
{
vis[p]=true;
if(min2>x[p].num)
{
min2=x[p].num;
minp=p;
}
p=x[p].po2;
}
cost1=0;
cost2=0;
p=minp;
while(p!=x[minp].po2)
{
cost1+=x[po[p]].num+min2;
cost2+=x[po[p]].num+minnum;
p=po[p];
}
ans+=min(cost1,cost2+2*(min2+minnum));
}
}
printf("%d\n",ans);
}
return 0;
}