HDU 1199 Color the Ball

Color the Ball

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 5631    Accepted Submission(s): 1395

Problem Description

There are infinite balls in a line (numbered 1 2 3 ....), and initially all of them are paint black. Now Jim use a brush paint the balls, every time give two integers a b and follow by a char 'w' or 'b', 'w' denotes the ball from a to b are painted white, 'b' denotes that be painted black. You are ask to find the longest white ball sequence.

 

Input

First line is an integer N (<=2000), the times Jim paint, next N line contain a b c, c can be 'w' and 'b'.

There are multiple cases, process to the end of file.

 

Output

Two integers the left end of the longest white ball sequence and the right end of longest white ball sequence (If more than one output the small number one). All the input are less than 2^31-1. If no such sequence exists, output "Oh, my god".

 

Sample Input

3
1 4 w
8 11 w
3 5 b

 

Sample Output

8 11
线段树区间覆盖的问题，问题是数字范围太大，所以要离散化。当然也可以不用离散化作，即动态开点。
这道题目的测试数据比较弱，所以我用了动态开点，要是数据强一点，可能会内存超限，
#include <iostream>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <algorithm>
#include <math.h>

using namespace std;
typedef long long int LL;
const int maxn=2*1e3;
LL mmax[maxn*35];
LL lmax[maxn*35];
LL rmax[maxn*35];
int c[maxn*35];
int l[maxn*35];
int r[maxn*35];
LL ll[maxn*35];
LL rr[maxn*35];
int n;
int p;
int newnode()
{
    l[p]=r[p]=-1;
    lmax[p]=rmax[p]=mmax[p]=0;
    ll[p]=rr[p]=-1;
    return p++;
}
void pushdown(int node,LL L,LL R)
{
    if(!(L==R))
    {
          if(l[node]==-1) l[node]=newnode();
        if(r[node]==-1) r[node]=newnode();
    }
    if(c[node]!=-1)
    {
        if(c[node])
        {
            lmax[node]=rmax[node]=mmax[node]=R-L+1;
            ll[node]=L,rr[node]=R;
        }
        else
        {
            lmax[node]=rmax[node]=mmax[node]=0;
            ll[node]=rr[node]=-1;
        }

        c[l[node]]=c[r[node]]=c[node];
        c[node]=-1;
    }
}
void pushup(int node,LL L,LL R)
{
    LL mid=(L+R)>>1;
    
    pushdown(l[node],L,mid);
    pushdown(r[node],mid+1,R);
    if(lmax[l[node]]==(mid-L+1))
        lmax[node]=lmax[l[node]]+lmax[r[node]];
    else
        lmax[node]=lmax[l[node]];
    if(rmax[r[node]]==(R-mid))
        rmax[node]=rmax[r[node]]+rmax[l[node]];
    else
        rmax[node]=rmax[r[node]];
    mmax[node]=max(lmax[r[node]]+rmax[l[node]],max(mmax[l[node]],mmax[r[node]]));
    if(mmax[node]==mmax[l[node]])
        ll[node]=ll[l[node]],rr[node]=rr[l[node]];
    else if(mmax[node]==lmax[r[node]]+rmax[l[node]])
        ll[node]=mid-rmax[l[node]]+1,rr[node]=mid+lmax[r[node]];
    else
        ll[node]=ll[r[node]],rr[node]=rr[r[node]];

}

void update(int node,LL begin,LL end,LL L,LL R,int tag)
{

    if(L<=begin&&end<=R)
    {
        c[node]=tag;
        if(l[node]==-1) l[node]=newnode();
        if(r[node]==-1) r[node]=newnode();
        pushdown(node,begin,end);
        return;
    }
    if(l[node]==-1) l[node]=newnode();
    if(r[node]==-1) r[node]=newnode();
    pushdown(node,begin,end);
    int mid=(begin+end)>>1;

    if(L<=mid) update(l[node],begin,mid,L,R,tag);
    if(R>mid) update(r[node],mid+1,end,L,R,tag);
    pushup(node,begin,end);
}
int main()
{

    while(scanf("%d",&n)!=EOF)
    {
        p=0;
        int root=newnode();
        LL a,b;
        char cc;
        LL len=(1<<31)-1;
        int tag;
        update(root,1,len,1,len,0);
        memset(c,-1,sizeof(c));
      for(int i=1;i<=n;i++)
        {
            scanf("%lld%lld %c",&a,&b,&cc);
            if(cc=='w') tag=1;
            else tag=0;
            update(root,1,len,a,b,tag);
        }
        if(ll[root]==-1)
            printf("Oh, my god\n");
        else
            printf("%lld %lld\n",ll[root],rr[root]);
    }
    return 0;
}