UVA 1468 Restaurant ?

#include<iostream>#include<cstdio>#include<cstring>#include<algorithm>using namespace std;#define rep(i,a,b) for(int i=(a);i<(b);i++)#define ss(x) scanf("%d",&x)const int maxn=60000+10;int y,ax,ay,bx,by,m,n,h[maxn];int main(){    int t;    ss(t);    while(t--)    {        ss(m);ss(n);        int a,b;        ss(ax);ss(ay);ss(bx);ss(by);        if(ax>bx) swap(ax,bx);        y=ay;        memset(h,0x7f,sizeof(h));        rep(i,2,n) {ss(a);ss(b);h[a]=min(h[a],abs(y-b));}        h[ax]=h[bx]=0;        rep(i,ax+1,bx) h[i]=min(h[i],h[i-1]+1);        for(int i=bx;i>ax;i--) h[i]=min(h[i],h[i+1]+1);        int ans=0;        rep(i,ax+1,bx) if(h[i]) ans+=min(h[i]-1,y)+min(h[i]-1,m-y-1)+1;        cout<<ans<<endl;    }    return 0;}