hdu 3874 树状数组

Necklace

Time Limit: 15000/5000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 2447    Accepted Submission(s): 865


Problem Description
Mery has a beautiful necklace. The necklace is made up of N magic balls. Each ball has a beautiful value. The balls with the same beautiful value look the same, so if two or more balls have the same beautiful value, we just count it once. We define the beautiful value of some interval [x,y] as F(x,y). F(x,y) is calculated as the sum of the beautiful value from the xth ball to the yth ball and the same value is ONLY COUNTED ONCE. For example, if the necklace is 1 1 1 2 3 1, we have F(1,3)=1, F(2,4)=3, F(2,6)=6.

Now Mery thinks the necklace is too long. She plans to take some continuous part of the necklace to build a new one. She wants to know each of the beautiful value of M continuous parts of the necklace. She will give you M intervals [L,R] (1<=L<=R<=N) and you must tell her F(L,R) of them.
 
Input
The first line is T(T<=10), representing the number of test cases.
  For each case, the first line is a number N,1 <=N <=50000, indicating the number of the magic balls. The second line contains N non-negative integer numbers not greater 1000000, representing the beautiful value of the N balls. The third line has a number M, 1 <=M <=200000, meaning the nunber of the queries. Each of the next M lines contains L and R, the query.
 
Output
For each query, output a line contains an integer number, representing the result of the query.
 
Sample Input
2
6
1 2 3 4 3 5
3
1 2
3 5
2 6
6
1 1 1 2 3 5
3
1 1
2 4
3 5
 
Sample Output
3
7
14
1
3
6
 
题目大意:有N个魔球,每个魔球都有自己的价值,M条查询(L,R)的价值和(同一价值的只算一次)。
 
#include<iostream>
#include<cstdio>
#include<map>
#include<algorithm>
using namespace std;

int dit[50010];
__int64 ans[200010];
__int64 f[50010];

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

struct query
{
    int lp,rp,id;
}q[200010];

bool mycomp(const query &a,const query &b)
{
    if(a.rp==b.rp) return a.lp<b.lp;
    return a.rp<b.rp;
}

void swap(int &a,int &b){ int t=a;a=b;b=t;}

void add(int x,int d,int n)
{
    while(x<=n){
        f[x]+=d;x+=lowbit(x);
    }
}

__int64 sum(int x)
{
    __int64 ret=0;
    while(x>=1){
        ret+=f[x];x-=lowbit(x);
    }
    return ret;
}

int main()
{
    int n,m,i,rp,t,x;
    map<int,int> mp;
    scanf("%d",&t);
    while(t--)
    {
        mp.clear();
        memset(f,0,sizeof(f));
        scanf("%d",&n);
        for(i=1;i<=n;i++) scanf("%d",&dit[i]);
        scanf("%d",&m);
        for(i=0;i<m;i++)
        {
            scanf("%d %d",&q[i].lp,&q[i].rp);
            if(q[i].lp>q[i].rp) swap(q[i].lp,q[i].rp);
            q[i].id=i;
        }
        sort(q,q+m,mycomp);
        rp=1;
        for(i=0;i<m;i++)
        {
            while(rp<=q[i].rp)
            {
                x=dit[rp];
                if(mp[x]!=0) add(mp[x],-x,n);
                add(rp,x,n);
                mp[x]=rp;
                rp++;
            }
            ans[q[i].id]=sum(q[i].rp)-sum(q[i].lp-1);
        }
        for(i=0;i<m;i++) printf("%I64d
",ans[i]);
    }
    return 0;
}
原文地址:https://www.cnblogs.com/xiong-/p/3585206.html