bzoj 3032 七夕祭 | 中位数

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
#include<cmath>

#define md
#define ll long long
#define inf (int) 1e9
#define eps 1e-8
#define N 200010
using namespace std;
int a
,p
[2],c
; 
int K,n,m;
ll solve(int d,int ave,int mx)
{
	memset(a,0,sizeof(a));
	for (int i=1;i<=K;i++) a[p[i][d]]++;
	int sum=0;
	for (int i=1;i<=K;i++) c[i]=c[i-1]+a[i]-ave;
	sort(c+1,c+mx+1);
	int mid=c[(mx+1)>>1];
	ll ans=0;
	for (int i=1;i<=mx;i++) ans+=abs(c[i]-mid);
	return ans;
}
	
int main()
{
	scanf("%d%d%d",&n,&m,&K);
	for (int i=1;i<=K;i++)
	{
		scanf("%d%d",&p[i][0],&p[i][1]);
	}
	int b=0; ll ans=0;
	if (K%n==0) { b++; ans+=solve(0,K/n,n); }
	if (K%m==0) { b+=2; ans+=solve(1,K/m,m); }
	if (b==0) printf("impossible\n");
	  else if (b==1) printf("row %lld\n",ans);
	    else if (b==2) printf("column %lld\n",ans);
	      else printf("both %lld\n",ans);
	return 0;
}