BZOJ 2276 Temperature

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define maxn 1000050
using namespace std;
int n,l[maxn],r[maxn],q[maxn],h=1,t=0,ans=0;
int read()
{
    char ch;int data=0,f=1;
    while (ch<‘0‘ || ch>‘9‘)
    {
        if (ch==‘-‘) f=-1;
        ch=getchar();
    }
    while (ch>=‘0‘ && ch<=‘9‘)
    {
        data=data*10+ch-‘0‘;
        ch=getchar();
    }
    return data*f;
}
int main()
{
    n=read();
    for (int i=1;i<=n;i++) l[i]=read(),r[i]=read();
    ans=1;q[++t]=1;
    for (int i=2;i<=n;i++)
    {
        while ((h<=t) && (l[i]>=l[q[t]])) t--;
        q[++t]=i;
        while ((h<=t) && (l[q[h]]>r[i])) h++;
        ans=max(ans,i-q[h-1]);
    }
    printf("%d\n",ans);
    return 0;
}