hdu 3874 树状数组+离线处理

标签：hdu

题意：

这和hdu 3333 根本就是一道题   链接：http://blog.csdn.net/u013382399/article/details/45689977

思路：

同hdu 3333  

code：

#include<cstdio>
#include<iostream>
#include<cstring>
#include<algorithm>
#include<vector>
#include<string>
#include<queue>
#include<map>
#include<set>
#include<cmath>
#include<cstdlib>
using namespace std;

#define INF 0x3f3f3f3f
#define PI acos(-1.0)
#define mem(a, b) memset(a, b, sizeof(a))
#define mod 1000000007
typedef pair<int,int> pii;
typedef long long LL;
//------------------------------
const int maxn = 50005;
const int maxq = 200005;

struct node{
    int s, e, id;
    bool operator < (const node nt) const{
        if(e != nt.e)
            return e < nt.e;
        else return s < nt.s;
    }
}qujian[maxq];
int n,q;
LL a[maxn];
LL ans[maxq];

struct BIT
{
    long long C[maxn];
    void init()
    {
        memset(C, 0, sizeof(C));
    }
    int lowbit(int x)
    {
        return -x&x;
    }
    long long get_Sum(int x)
    {
        long long ret = 0;
        while(x > 0)
        {
            ret += C[x];
            x -= lowbit(x);
        }
        return ret;
    }
    void add(int x,long long v)
    {
        while(x <= n)
        {
            C[x] += v;
            x += lowbit(x);
        }
    }
}bit;


void init(){
    scanf("%d",&n);
    for(int i = 1; i <= n; i++){
        scanf("%I64d",&a[i]);
    }
    scanf("%d",&q);
    int st, ed;
    for(int i = 0; i < q; i++){
        scanf("%d%d",&st, &ed);
        qujian[i].s = st;
        qujian[i].e = ed;
        qujian[i].id = i;
    }
}
map<long long, int> ma;
void solve(){
    sort(qujian, qujian+q);

//    for(int i = 0; i < q; i++){
//        printf("==%d %d==\n",qujian[i].s, qujian[i].e);
//
//    }


    ma.clear();
    bit.init();
    int start_ = 1;
    for(int i = 0; i < q; i++){
        for(int j = start_; j <= qujian[i].e; j++){
            if(ma.count(a[j])){
                bit.add(ma[a[j]],-a[j]);
            }
            bit.add(j,a[j]);
            ma[a[j]] = j;
        }
        ans[qujian[i].id] = bit.get_Sum(qujian[i].e) - bit.get_Sum(qujian[i].s-1);
        start_ = qujian[i].e + 1;
    }
    for(int i = 0; i < q; i++){
        printf("%I64d\n",ans[i]);
    }
}
int main(){
    int t;
    scanf("%d",&t);
    while(t--){
        init();
        solve();
    }
    return 0;
}

hdu 3874 树状数组+离线处理

标签：hdu

原文地址：http://blog.csdn.net/u013382399/article/details/45690737