HDU1556(树状数组)

Color the ball

Time Limit: 9000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 17044    Accepted Submission(s): 8513

Problem Description

N个气球排成一排，从左到右依次编号为1,2,3....N.每次给定2个整数a b(a <= b),lele便为骑上他的“小飞鸽"牌电动车从气球a开始到气球b依次给每个气球涂一次颜色。但是N次以后lele已经忘记了第I个气球已经涂过几次颜色了，你能帮他算出每个气球被涂过几次颜色吗？

 

Input

每个测试实例第一行为一个整数N,(N <= 100000).接下来的N行，每行包括2个整数a b(1 <= a <= b <= N)。
当N = 0，输入结束。

 

Output

每个测试实例输出一行，包括N个整数，第I个数代表第I个气球总共被涂色的次数。

 

Sample Input

3

1 1

2 2

3 3

3

1 1

1 2

1 3

0

 

Sample Output

1 1 1

3 2 1

 树状数组入门，区间更新，单点查询

//2016.8.10
//树状数组，区间更新，单点查询
#include<iostream>
#include<cstdio>
#include<cstring>

using namespace std;

int arr[100005], n;//arr[i]表示i管辖的范围内数字之和

int lowbit(int x){return x&(-x);}

int add(int pos, int tt)
{
    for(int i = pos; i <= n; i+=lowbit(i))
      arr[i] += tt;
    return 0;
}

int query(int pos)
{
    int sum = 0; 
    for(int i = pos; i > 0; i-=lowbit(i))
      sum+=arr[i];
    return sum;
}

int main()
{
    int a, b;
    while(cin>>n)
    {
        memset(arr, 0, sizeof(arr));
        for(int i = 0; i < n; i++)
        {
            scanf("%d%d", &a, &b);
            add(a, 1);
            add(b+1, -1);
        }
        for(int i = 1; i <= n; i++)
          if(i == n)
            cout<<query(i)<<endl;
          else cout<<query(i)<<" ";
    }

    return 0;
}

// 2018-03-28

import java.util.*;
    
public class Main {

    public static void main(String[] args) {
        Scanner cin = new Scanner(System.in);
        
        int n;
        while(cin.hasNext()) {
            n = cin.nextInt();
            if(n == 0)break;
            BinaryIndexedTrees bit = new BinaryIndexedTrees(n);
            int l, r;
            for(int i = 0; i < n; i++) {
                l = cin.nextInt();
                r = cin.nextInt();
                bit.updata(l, r, 1);
            }
            
            for(int i = 1; i <= n; i++) {
                if(i == n)System.out.printf("%d 
", bit.query(i));
                else System.out.printf("%d ", bit.query(i));
            }
        }
    }
}
    
class BinaryIndexedTrees {
    /*
     * 区间更新，单点查询
     */
    int n;
    int [] e;
    
    BinaryIndexedTrees(int _n) {
        this.n = _n;
        e = new int[n+1];
    }
    
    // x+lowbit(x)表示到达x的父节点
    // x-lowbit(x)表示到达x点管辖区间的下个区间的管辖点
    int lowbit(int x) {
        return x&(-x);
    }
    
    void add(int pos, int val) {
        for(int i = pos; i <= n; i+=lowbit(i))
            e[i] += val;
    }
    
    int query(int pos) {
        int sum = 0;
        for(int i = pos; i > 0; i-=lowbit(i))
            sum += e[i];
        return sum;
    }
    
    // 给[l, r]区间内的每个数加上val
    void updata(int l, int r, int val) {
        add(l, val);
        add(r+1, -val);
        
    }
}