poj2777 Count Color

Count Color
Time Limit: 1000MS
 
Memory Limit: 65536K
Total Submissions: 26254
 
Accepted: 7833
Description
Chosen Problem Solving and Program design as an optional course, you are required to solve all kinds of problems. Here, we get a new problem. 
There is a very long board with length L centimeter, L is a positive integer, so we can evenly divide the board into L segments, and they are labeled by 1, 2, ... L from left to right, each is 1 centimeter long. Now we have to color the board - one segment with only one color. We can do following two operations on the board: 
1. "C A B C"Color the board from segment A to segment B with color C. 
2. "P A B"Output the number of different colors painted between segment A and segment B (including). 
In our daily life, we have very few words to describe a color (red, green, blue, yellow…), so you may assume that the total number of different colors T is very small. To make it simple, we express the names of colors as color 1, color 2, ... color T. At the beginning, the board was painted in color 1. Now the rest of problem is left to your. 
Input
First line of input contains L (1 <= L <= 100000), T (1 <= T <= 30) and O (1 <= O <= 100000). Here O denotes the number of operations. Following O lines, each contains "C A B C"or "P A B"(here A, B, C are integers, and A may be larger than B) as an operation defined previously.
Output
Ouput results of the output operation in order, each line contains a number.
Sample Input

2 2 4
C 1 1 2
P 1 2
C 2 2 2
P 1 2

Sample Output

2
1

Source
POJ Monthly--2006.03.26,dodo
変更されたセグメントツリーがあり、色にはビット演算が必要です.
コードが気持ち悪いので、見なくてもいいです.

#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std;

typedef struct
{
    int l,r,lazy,vis;
}Tree;

char str[5];
Tree tree[500000];
int num;
int ans;

void Build(int t,int l,int r)
{
    int mid;
    tree[t].lazy=0;
    tree[t].l=l;
    tree[t].r=r;
    if (l==r) return;
    mid=(l+r)/2;
    Build(2*t+1,l,mid);
    Build(2*t+2,mid+1,r);
}

void Color(int t,int x,int y,int c)
{
    int l,r,mid,i,j,k;
    l=tree[t].l;
    r=tree[t].r;
    mid=(l+r)/2;
    if (l==x && r==y)
    {
        tree[t].vis=c;
        tree[t].lazy=1;
        return;
    }
    if (tree[t].lazy==1)
    {
        tree[t].lazy=0;
        Color(2*t+1,l,mid,tree[t].vis);
        Color(2*t+2,mid+1,r,tree[t].vis);
    }
    if (x<=mid)
    {
        Color(2*t+1,x,min(mid,y),c);
    }
    if (y>=mid+1)
    {
        Color(2*t+2,max(x,mid+1),y,c);
    }
    i=2*t+1;
    j=2*t+2;
    tree[t].vis=(tree[i].vis | tree[j].vis);
}

void Find(int t,int x,int y)
{
    int l,r,mid,i;
    l=tree[t].l;
    r=tree[t].r;
    if (l==x && r==y)
    {
        ans=(ans | tree[t].vis);
        return;
    }
    mid=(l+r)/2;
    if (tree[t].lazy==1)
    {
        tree[t].lazy=0;
        Color(2*t+1,l,mid,tree[t].vis);
        Color(2*t+2,mid+1,r,tree[t].vis);
    }
    if (x<=mid)
    {
        Find(2*t+1,x,min(y,mid));
    }
    if (y>=mid+1)
    {
        Find(2*t+2,max(x,mid+1),y);
    }
}

int main()
{
    int i,j,n,q,x,y,z,cnt;
    while(scanf("%d%d%d",&n,&num,&q)!=EOF)
    {
        Build(0,0,n-1);
        Color(0,0,n-1,1);
        while(q--)
        {
            scanf("%s",str);
            scanf("%d%d",&x,&y);
            if (x>y)
            {
                swap(x,y);
            }
            if (str[0]=='C')
            {
                scanf("%d",&z);
                Color(0,x-1,y-1,1<<(z-1));
            }
            else
            {
                ans=0;
                Find(0,x-1,y-1);
                cnt=0;
                for (i=0;i<num;i++)
                {
                    if ((ans & (1<<i))!=0) cnt++;
                }
                printf("%d
",cnt);
            }
        }
    }
    return 0;
}