ecfinal L. Fenwick Tree

考虑到树状数组是一颗树，然后染色的做法

#include <bits/stdc++.h>
/*
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/hash_policy.hpp>
*/
using namespace std;

const double eps = 1e-10;
const double pi = 3.1415926535897932384626433832795;
const double eln = 2.718281828459045235360287471352;

#define f(i, a, b) for (int i = a; i <= b; i++)
#define scan(x) scanf("%d", &x)
#define mp make_pair
#define pb push_back
#define lowbit(x) (x&(-x))

#define fi first
#define se second
#define SZ(x) int((x).size())
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define summ(a) (accumulate(all(a), 0ll))

typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;

using ll=long long;

int tt,n,a[(int)1e5+9],ans,cn[(int)1e5+9];
char c;
vi g[(int)1e5+9]; 

void dfs(int x){
    a[x]=0;
    bool ok=1;
    for(auto it:g[x]){
        if(a[it]){
            dfs(it);
            ok=0;
        }
    }
    ans+=ok;
}

int main()
{
    for(int i=1;i<=1e5;++i){
        int tmp=i+lowbit(i);
        if(tmp<=1e5)g[tmp].push_back(i);
    }
    scanf("%d",&tt);
    f(sb,1,tt){
        ans=0;
        scanf("%d",&n);
        for(int i=1;i<=n;++i)scanf(" %c",&c),a[i]=c=='1',cn[i]=0;
        for(int i=n;i;--i){
            if(a[i]){
                dfs(i);
                int tmp=i+lowbit(i);
                if(tmp<=n)cn[tmp]+=1;
            }
        }
        for(int i=1;i<=n;++i)ans+=cn[i]==1;
        printf("%d\n",ans);
    }
    return 0;
}