QOJ.ac

QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#642143#8551. DFS Order 5youthpaulWA 34ms3856kbC++203.6kb2024-10-15 10:52:362024-10-15 10:52:37

Judging History

你现在查看的是最新测评结果

  • [2024-10-15 10:52:37]
  • 评测
  • 测评结果:WA
  • 用时:34ms
  • 内存:3856kb
  • [2024-10-15 10:52:36]
  • 提交

answer

#include<bits/stdc++.h>
#define fore(i,l,r)	for(int i=(int)(l);i<(int)(r);++i)
#define fi first
#define se second
#define endl '\n'
#define ull unsigned long long
#define ALL(v) v.begin(), v.end()
#define Debug(x, ed) std::cerr << #x << " = " << x << ed;

const int INF=0x3f3f3f3f;
const long long INFLL=1e18;

typedef long long ll;

template <typename T>
struct Fenwick {
    int n;
    std::vector<T> a;

    Fenwick(int n_ = 0) {
        init(n_);
    }
    
    void init(int n_) {
        n = n_;
        a.assign(n + 5, T{});
    }

    void update(int p, const T &v) { //在位置 p 加 v
        while(p <= n){
            a[p] += v;
            p += p & -p;
        }
    }
    
    T query(int p) {
        T ans{};
        while(p > 0){
            ans += a[p];
            p -= p & -p;
        }
        return ans;
    }

    T rangeSum(int l, int r) {
        return query(r) - query(l - 1); //前缀和
    }

    int find_first(T sum){ //找到第一个 query(p) >= sum 的位置 p
        int p = 0;
        T val = 0;
        for(int i = std::__lg(n); i >= 0; --i)
            if((p | 1 << i) <= n && val + a[p | 1 << i] < sum){
                p |= 1 << i;
                val += a[p];
            }
        return p + 1;
    }

    int find_last(T sum){ //找到最后一个 query(p) <= sum 的位置 p
        int p = 0;
        T val = 0;
        for(int i = std::__lg(n); i >= 0; --i)
            if((p | 1 << i) <= n && val + a[p | 1 << i] <= sum){
                p |= 1 << i;
                val += a[p];
            }
        return p;
    }
};

const int N = 100005;
const int K = 17;

std::vector<int> g[N];
int f[N][K + 1];
int h[N];
int dfn[N];
int up[N];
int tot;
int sz[N];

void dfs0(int u, int fa){
	h[u] = h[fa] + 1;
	f[u][0] = fa;
	dfn[u] = ++tot;
	sz[u] = 1;
	for(int k = 1; (1 << k) <= h[u]; ++k)
		f[u][k] = f[f[u][k - 1]][k - 1];
	for(auto v : g[u])
		if(v != fa){
			dfs0(v, u);
			sz[u] += sz[v];
		}
	up[u] = tot;
}

int lca(int u, int v){
	if(h[u] < h[v]) std::swap(u, v);
	for(int k = K; k >= 0; --k)
		if(h[u] - (1 << k) >= h[v])
			u = f[u][k];
	if(u == v) return u;
	for(int k = K; k >= 0; --k)
		if(f[u][k] != f[v][k]){
			u = f[u][k];
			v = f[v][k];
		}
	return f[u][0];
}

int main(){
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    std::cout.tie(nullptr);
    int n, q;
    std::cin >> n >> q;
    fore(i, 1, n){
    	int u, v;
    	std::cin >> u >> v;
    	g[u].push_back(v);
    	g[v].push_back(u);
    }
    
    dfs0(1, 0);
    
    Fenwick<int> fen(n);
    
    while(q--){
    	int m;
    	std::cin >> m;
    	std::vector<int> a(m);
    	fore(i, 0, m) std::cin >> a[i];
    	std::vector<int> p;
    	
    	auto check = [&]() -> bool {
    		if(m == 1) return true;
    		p.push_back(dfn[a[0]]);
    		fen.update(dfn[a[0]], 1);
    		if(a[0] != 1){
    			p.push_back(1);
    			fen.update(1, 1);
    		}
    		
    		fore(i, 1, m){
    			int u = a[i - 1], w = a[i];
    			if(fen.rangeSum(dfn[w], up[w])) return false;
    			if(f[w][0] == u){
    				fen.update(dfn[w], 1);
    				p.push_back(dfn[w]);
    				continue;
    			}
    			if(fen.rangeSum(dfn[u], up[u]) != sz[u]) return false;
    			if(lca(u, f[w][0]) == f[w][0] && lca(u, w) != w){
    				fen.update(dfn[w], 1);
    				p.push_back(dfn[w]);
    				continue;
    			}
    			return false;
   		 	}	
   		 	
   		 	return true;
    	};
    	
    	std::cout << (check() ? "Yes" : "No") << endl;
    	for(auto x : p)	fen.update(x, -1);
    }
    
    return 0;
}














Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 1ms
memory: 3568kb

input:

6 7
1 2
1 3
2 4
3 5
2 6
2 4 1
2 4 2
2 4 3
2 4 4
2 4 5
2 4 6
6 1 2 6 4 3 5

output:

No
No
Yes
No
No
Yes
Yes

result:

ok 7 tokens

Test #2:

score: -100
Wrong Answer
time: 34ms
memory: 3856kb

input:

10 100000
7 2
1 7
7 10
8 6
8 7
1 3
4 5
9 5
5 8
8 8 9 7 2 8 1 6 1
4 8 3 5 2
6 7 10 3 9 9 1
1 1
8 10 3 2 9 3 8 7 3
7 5 6 2 8 5 9 1
6 3 4 6 2 1 3
5 8 9 2 4 9
1 3
2 1 5
5 8 5 1 7 9
10 5 2 9 2 6 4 10 6 3 8
3 4 5 8
2 8 4
9 4 10 1 2 4 3 3 6 3
1 3
6 1 1 6 8 3 1
3 7 3 2
3 9 1 5
4 3 7 8 10
9 4 2 3 10 2 5 4 3 ...

output:

No
No
No
Yes
No
No
No
No
Yes
No
No
No
No
No
No
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
No
No
No
No
No
No
Yes
No
No
No
No
No
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
No
No
Yes
Yes
No
No
No
No
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
N...

result:

wrong answer 899th words differ - expected: 'No', found: 'Yes'