HDU 3333 Turing Tree

Turing Tree

http://acm.hdu.edu.cn/showproblem.php?pid=3333

分析：

　　这道题目叫 图灵树。

　　离线+树状数组。

　　维护到每个右端点的答案，直接查询左端点，树状数组维护。一个数字不能出现两次，会发现如果出现了多个数，最右边的数可以代替左边的所有数，所以只加入最右边一个数即可。

代码：

#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<iostream>
#include<cctype>
#include<set>
#include<vector>
#include<queue>
#include<map>
#define pa pair<int,int>
#define mp make_pair
#define fi(s) freopen(s,"r",stdin);
#define fo(s) freopen(s,"w",stdout);
using namespace std;
typedef long long LL;

inline int read() {
    int x=0,f=1;char ch=getchar();for(;!isdigit(ch);ch=getchar())if(ch=='-')f=-1;
    for(;isdigit(ch);ch=getchar())x=x*10+ch-'0';return x*f;
}

const int N = 30005;

struct Bit{
    int n; LL sum[N];
    void Clear() { memset(sum, 0, sizeof(sum)); }
    void update(int p,int v) {
        for (; p<=n; p+=(p&(-p))) sum[p] += v;
    }
    LL query(int p) {
        LL ans = 0;
        for (; p; p-=(p&(-p))) ans += sum[p];
        return ans;
    }
}bit;
int last[N], disc[N], a[N];
LL ans[100005]; // 数据范围！ 
vector< pa > vec[N];

void solve() { 
    int n = read(), cnt = 1;
    for (int i=1; i<=n; ++i) 
        a[i] = read(), disc[i] = a[i];
    sort(disc + 1, disc + n + 1);
    for (int i=2; i<=n; ++i) if (disc[i] != disc[cnt]) disc[++cnt] = disc[i];
    for (int i=1; i<=n; ++i) 
        a[i] = lower_bound(disc + 1, disc + cnt + 1, a[i]) - disc;
    int Q = read();
    for (int i=1; i<=Q; ++i) {
        int l = read(), r = read();
        vec[r].push_back(mp(l, i));
    }
    bit.n = n;
    for (int i=1; i<=n; ++i) {
        if (last[a[i]]) bit.update(last[a[i]], -disc[a[last[a[i]]]]);
        bit.update(i, disc[a[i]]);
        last[a[i]] = i;
        for (int sz=vec[i].size(),j=0; j<sz; ++j) 
            ans[vec[i][j].second] = bit.query(i) - bit.query(vec[i][j].first - 1);
    }
    for (int i=1; i<=Q; ++i) printf("%lld
",ans[i]);
    bit.Clear();
    memset(last, 0, sizeof(last));
    for (int i=1; i<=n; ++i) vec[i].clear();
}

int main() {
    int T = read();
    while (T--) 
        solve();
    return 0;
}