UvaLive-4851-Restaurant

#include<cstdio>
#include<cstring>
#include<iostream>
using namespace std;
const int maxn=60001;
const int inf=1<<28;
int miny[maxn],maxy[maxn],h[maxn];
int main()
{
int T;
scanf("%d",&T);
int n,m;
int x1,y1,x2,y2;
while(T--)
{
scanf("%d%d",&n,&m);
scanf("%d%d%d%d",&x1,&y1,&x2,&y2);
if(x1>x2)
{
swap(x1,x2);
swap(y1,y2);
}
for(int i=x1+1;i<x2;i++)
{
miny[i]=inf;
maxy[i]=-inf;
}
for(int i=2;i<m;i++)
{
int ita,itb;
scanf("%d%d",&ita,&itb);
if(itb>=y1)
miny[ita]=min(miny[ita],itb);
if(itb<=y1)
maxy[ita]=max(maxy[ita],itb);
}
for(int i=x1;i<=x2;i++)
h[i]=min(y1-maxy[i],miny[i]-y1);
h[x1]=0;
for(int i=x1+1;i<x2;i++)
h[i]=min(h[i],h[i-1]+1);
h[x2]=0;
for(int i=x2-1;i>x1;i--)
h[i]=min(h[i],h[i+1]+1);
long long ans=0;
for(int i=x1;i<=x2;i++)
if(h[i])
{
ans++;
ans+=min(h[i]-1,y1);
ans+=min(h[i]-1,n-y1-1);
}
cout<<ans<<endl;
}
return 0;
}