hdu Largest Rectangle in a Histogram

#include"stdio.h"
__int64 h[100010],ans,temp;
int l[100010],r[100010];
int main()
{
    int n,i,j;
    while(scanf("%d",&n),n)
    {
        for(i=1;i<=n;i++)
        {
            scanf("%I64d",&h[i]);
            l[i]=r[i]=i;
        }
        h[0]=h[n+1]=-1;
        for(i=1;i<=n;i++)
        {
            while(h[l[i]-1]>=h[i])
                l[i]=l[l[i]-1];
        }
        for(i=n;i>=1;i--) //注意这个顺序，tle了好几次都是因为用的是i++，i<=n
        {
            while(h[r[i]+1]>=h[i])
                r[i]=r[r[i]+1];
        }
        ans=0;
        for(i=1;i<=n;i++)
        {
            temp=h[i]*(r[i]-l[i]+1);
            if(temp>ans) ans=temp;
        }
       printf("%I64d\n",ans);
    }
    return 0;
}