Submission #84474

#	Time	Username	Problem	Language	Result	Execution time	Memory
84474		inom	Birthday gift (IZhO18_treearray)	C++14	56 / 100	1610 ms	108896 KiB

treearray

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;

const int MX = 200 * 1000 + 7;
const int LG = 18;

vector<int> g[MX];
int tin[MX], tout[MX];
int timer = 1;
int p[MX][LG];
int a[MX];
set<int> x[MX], y[MX];

void dfs(int v = 1, int par = 1) {
    tin[v] = timer;
    timer++;
    p[v][0] = par;
    for (int i = 1; i < LG; i++) {
        p[v][i] = p[p[v][i - 1]][i - 1];
    }
    for (int to : g[v]) {
        if (to != par) {
            dfs(to, v);
        }
        
    }
    tout[v] = timer;
    timer++;
}

bool isAncestor(int u, int v) {
    return tin[u] <= tin[v] && tout[u] >= tout[v];
}

int getLCA(int u, int v) {
    if (isAncestor(u, v)) {
        return u;
    } else if (isAncestor(v, u)) {
        return v;
    } else {
        for (int i = LG - 1; i >= 0; i--) {
            if (!isAncestor(p[u][i], v)) {
                u = p[u][i];
            }
        }
        return p[u][0];
    }
}

int main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
#endif
    int n, k, q;
    scanf("%d %d %d", &n, &k, &q);
    for (int i = 1; i <= n - 1; i++) {
        int u, v;
        scanf("%d %d", &u, &v);
        g[u].push_back(v);
        g[v].push_back(u);
    }
    for (int i = 1; i <= n; i++) {
        x[i].insert(k + 1);
        y[i].insert(k + 1);
    }
    dfs();
    for (int i = 1; i <= k; i++) {
        scanf("%d", &a[i]);
        x[a[i]].insert(i);
        if (i > 1) {
            y[getLCA(a[i - 1], a[i])].insert(i - 1);
        }
    }
    for (int i = 0; i < q; i++) {
        int t;
        scanf("%d", &t);
        if (t == 1) {
            int pos, v;
            scanf("%d %d", &pos, &v);
            x[a[pos]].erase(pos);
            if (pos > 1) {
                y[getLCA(a[pos - 1], a[pos])].erase(pos - 1);
            }
            if (pos + 1 <= n) {
                y[getLCA(a[pos], a[pos + 1])].erase(pos);
            }
            a[pos] = v;
            x[a[pos]].insert(pos);
            if (pos > 1) {
                y[getLCA(a[pos - 1], a[pos])].insert(pos - 1);
            }
            if (pos + 1 <= n) {
                y[getLCA(a[pos], a[pos + 1])].insert(pos);
            }
        } else {
            int l, r, v;
            scanf("%d %d %d", &l, &r, &v);
            int p1 = *x[v].lower_bound(l), p2 = *y[v].lower_bound(l);
            if (p1 <= r) {
                printf("%d %d\n", p1, p1);
            } else if (p2 + 1 <= r) {
                printf("%d %d\n", p2, p2 + 1);
            } else {
                printf("-1 -1\n");
            }
        }
    }
}

Compilation message (stderr)

treearray.cpp: In function 'int main()':
treearray.cpp:59:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d %d", &n, &k, &q);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
treearray.cpp:62:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &u, &v);
         ~~~~~^~~~~~~~~~~~~~~~~
treearray.cpp:72:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &a[i]);
         ~~~~~^~~~~~~~~~~~~
treearray.cpp:80:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &t);
         ~~~~~^~~~~~~~~~
treearray.cpp:83:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d %d", &pos, &v);
             ~~~~~^~~~~~~~~~~~~~~~~~~
treearray.cpp:101:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d %d %d", &l, &r, &v);
             ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 26 / 26
• Subtask 4: 0 / 44