思路：
由于It is guaranteed that the total length of all given segments doesn't exceed (10^{5}).所以暴力的标记每个能够通过的点跑bfs就好了。
注意标记的时候借助(pair和map),如果映射到一维的话会爆(ll)吧。
代码：
const int maxn=1e5+100;
ll sx,sy,ex,ey,n;
struct node{
ll x,y,val,step;
};
int nx[8]={-1,-1,-1,0,0,1,1,1};
int ny[8]={-1,0,1,-1,1,-1,0,1};
map<PLL,ll>mp;
int main(){
sx=read,sy=read,ex=read,ey=read;
n=read;
for(ll i=1;i<=n;i++){
ll r=read,a=read,b=read;
for(ll j=a;j<=b;j++){
mp[{r,j}]=-1;
}
}
queue<PLL>q;
q.push({sx,sy});
mp[{sx,sy}]=0;
while(!q.empty()){
PLL t=q.front();q.pop();
if(t.first==ex&&t.second==ey){
cout<<mp[t]<<"
";return 0;
}
for(int i=0;i<8;i++){
PLL tmp={t.first+nx[i],t.second+ny[i]};
if(mp[tmp]==-1&&mp.count(tmp))
mp[tmp]=mp[t]+1,q.push(tmp);
}
}
cout<<mp[{ex,ey}];
return 0;
}