Submission #947433

#	Time	Username	Problem	Language	Result	Execution time	Memory
947433		weakweakweak	Capital City (JOI20_capital_city)	C++17	30 / 100	180 ms	94932 KiB

capital_city

//好吧，我很笨
#include <bits/stdc++.h>
using namespace std;

int lt[510000], rt[510000], cnt[510000], n, k, col[510000], revlt[510000], now = 0, l[510000], r[510000];
int pos[510000] = {0};

vector<int> e[510000];
vector<int> qs[510000];
set<int> st[510000];

int a[510000] = {0};
void update (int i, int val) {
    for (; i <= n; i += i & -i) a[i] += val;
}
int query (int i) {
    int res = 0;
    for (; i > 0; i -= i & -i) res += a[i];
    return res;
}
int query2 (int l, int r) {return query(r) - query(l - 1);}


void dfs (int i, int par) {
    lt[i] = ++now, revlt[now] = i;
    for (int j : e[i]) if (j != par) dfs(j, i);
    rt[i] = now;
}




struct SEGMN {
    int a[810000];
    void build (int lr, int rr, int id) {
        if (lr == rr) {
            a[id] = l[col[lr]];
            return;
        }
        int mid = (lr + rr) / 2;
        build (lr, mid, id << 1); build(mid + 1, rr, id << 1 | 1);
        a[id] = min(a[id << 1], a[id << 1 | 1]);
    }
    int query (int lr, int rr, int ql, int qr, int id) {
        if (ql <= lr and rr <= qr) return a[id];
        int res = INT_MAX, mid = (lr + rr) / 2;
        if (ql <= mid) res = min(res, query(lr, mid, ql, qr, id << 1));
        if (qr > mid ) res = min(res, query(mid + 1, rr, ql, qr, id << 1 | 1));
        return res;
    }
} segl;



struct SEGMX {
    int a[810000];
    void build (int lr, int rr, int id) {
        if (lr == rr) {
            a[id] = r[col[lr]];
            return;
        }
        int mid = (lr + rr) / 2;
        build (lr, mid, id << 1); build(mid + 1, rr, id << 1 | 1);
        a[id] = max(a[id << 1], a[id << 1 | 1]);
    }
    int query (int lr, int rr, int ql, int qr, int id) {
        if (ql <= lr and rr <= qr) return a[id];
        int res = -1, mid = (lr + rr) / 2;
        if (ql <= mid) res = max(res, query(lr, mid, ql, qr, id << 1));
        if (qr > mid ) res = max(res, query(mid + 1, rr, ql, qr, id << 1 | 1));
        return res;
    }
} segr;

int main () {
    ios_base::sync_with_stdio(false); cin.tie(0);
    cin >> n >> k;
    for (int i = 1; i < n; i++) {
        int x, y;
        cin >> x >> y;
        e[x].push_back(y);
        e[y].push_back(x);
    }
    int rt = 1;
    for (int i = 1; i <= n; i++) if (e[i].size() == 1) rt = i;
    dfs(rt, rt);

    for (int i = 1; i <= n; i++) {
        cin >> col[lt[i]];
        if (cnt[col[lt[i]]]++ == 0) l[col[lt[i]]] = r[col[lt[i]]] = lt[i];
        else l[col[lt[i]]] = min(l[col[lt[i]]], lt[i]),  r[col[lt[i]]] = max(r[col[lt[i]]], lt[i]); 
    }

    for (int i = 1; i <= k; i++) {
        qs[r[i]].push_back(l[i]);
        st[r[i]] . insert(l[i]);
    }

    segl.build(1, n, 1);
    segr.build(1, n, 1);
    int ans = k;
    for (int i = 1; i <= n; i++) {
        if (pos[col[i]]) update(pos[col[i]], -1);
        pos[col[i]] = i;
        update(i, 1);
        for (int j : qs[i]) {
            int wow1 = segl.query(1, n, j, i, 1), wow2 = segr.query(1, n, j, i, 1);  
            if (wow1 >= j and wow2 <= i) ans = min(ans, query2(j, i));
            else if (st[wow2].count(wow1) == 0) {
                qs[wow2].push_back(wow1);
                st[wow2].insert(wow1);
            }
        }   
    }

    cout << ans - 1 << '\n';
return 0;}

• Subtask 1: 0 / 1
• Subtask 2: 0 / 10
• Subtask 3: 30 / 30
• Subtask 4: 0 / 59