Submission #155586

#	Time	Username	Problem	Language	Result	Execution time	Memory
155586		HellAngel	Mergers (JOI19_mergers)	C++14	0 / 100	177 ms	29596 KiB

mergers

#include <bits/stdc++.h>
#define int long long
using namespace std;
const int maxn = 5e5 + 7;
const int maxState = (1 << 8);
int n, m, u, v, Min[maxn], Max[maxn], cnt, sum[maxn], st[maxn], last1 = 0, en[maxn], ITSum[maxn * 4], ITMax[4 * maxn];
vector<int> vt[maxn], col, ahihi;
int ans = 0;
set<int> St;
bool ok[maxn];
/// first: sum
/// second: last
void Update(int id, int l, int r, int pos, pair<int, int> x)
{
    if(l == r)
    {
        ITSum[id] = x.first;
        ITMax[id] = x.second;
        return;
    }
    int mid = l + r >> 1;
    if(pos <= mid) Update(id * 2,l , mid, pos, x);
    else Update(id * 2 + 1, mid + 1, r, pos, x);
    ITSum[id] = ITSum[id * 2] + ITSum[id * 2 + 1];
    ITMax[id] = max(ITMax[id * 2], ITMax[id * 2 + 1]);
}

pair<int, int> Get(int id, int l, int r, int u, int v)
{
    if(l > v || r < u) return {0, 0};
    if(u <= l && r <= v)
    {
        return {ITSum[id], ITMax[id]};
    }
    int mid = l + r >> 1;
    pair<int, int> gau1 = Get(id * 2, l, mid, u, v);
    pair<int, int> gau2 = Get(id * 2 + 1, mid + 1, r, u, v);
    return {gau1.first + gau2.first, max(gau1.second, gau2.second)};
}

void DFS(int u, int p)
{
    st[u] = ++cnt;
    for(auto v: vt[u])
    {
        if(v != p) DFS(v, u);
    }
    en[u] = cnt;
}

void DFS2(int u, int p, int last)
{
    if(ok[u]) last = u;
    int aha = 0;
    if(last1 >= 0) last1 = u;
    for(auto v: vt[u])
    {
        if(v != p)
        {
            aha++;
        }
    }
    if(aha != 1 && last1 > 0)
    {
        last1 = -last1;
    }
    for(auto v:vt[u])
    {
        if(v != p) DFS2(v, u, last);
    }
    if(!aha && last != -1)
    {
        St.insert(last);
    }
}

int32_t main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    if(fopen("test.inp", "r")) freopen("test.inp", "r", stdin), freopen("test.out", "w", stdout);
    cin >> n >> m;
    for(int i = 1; i <= m; i++) Min[i] = INT_MAX;
    for(int i = 1; i < n; i++)
    {
        int u, v;
        cin >> u >> v;
        vt[u].push_back(v);
        vt[v].push_back(u);
    }
    DFS(1, 1);
    for(int i = 1; i <= n; i++)
    {
        ahihi.push_back(i);
        int x;
        cin >> x;
        Max[x] = max(Max[x], st[i]);
        Min[x] = min(Min[x], st[i]);
        sum[x]++;
    }
    for(int i = 1; i <= m; i++) Update(1, 1, n, Min[i], {sum[i], Max[i]});
    for(int i = 1; i <= n; i++)
    {
        pair<int, int> gau = Get(1, 1, n, st[i], en[i]);
        if(gau.second <= en[i] && gau.first == en[i] - st[i] + 1)
        {
            ok[i] = true;
        }
    }
    DFS2(1, 1, -1);
    for(int i = 1; i <= st[-last1]; i++) if(ok[i]) ans++;
    cout << (ans > 1) + St.size() - 1;
}

Compilation message (stderr)

mergers.cpp: In function 'void Update(long long int, long long int, long long int, long long int, std::pair<long long int, long long int>)':
mergers.cpp:21:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
     int mid = l + r >> 1;
               ~~^~~
mergers.cpp: In function 'std::pair<long long int, long long int> Get(long long int, long long int, long long int, long long int, long long int)':
mergers.cpp:35:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
     int mid = l + r >> 1;
               ~~^~~
mergers.cpp: In function 'int32_t main()':
mergers.cpp:81:63: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     if(fopen("test.inp", "r")) freopen("test.inp", "r", stdin), freopen("test.out", "w", stdout);
                                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mergers.cpp:81:63: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]

• Subtask 1: 0 / 10
• Subtask 2: 0 / 24
• Subtask 3: 0 / 14
• Subtask 4: 0 / 22
• Subtask 5: 0 / 30