Submission #86782

#	Time	Username	Problem	Language	Result	Execution time	Memory
86782		inom	Birthday gift (IZhO18_treearray)	C++14	100 / 100	1442 ms	242552 KiB

treearray

#include<bits/stdc++.h>

#define pb push_back

using namespace std;

#pragma GCC optimize("Ofast")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,popcnt,abm,mmx,tune=native")
#pragma GCC optimize("fast-math")
#pragma warning(disable : 4996)

const int N = 2 * 1e5 + 10;

int n, m, q;
int node[N];
vector<int> verr[N];
int l = 1, timer = 1;
int tin[N], tout[N];
int up[N][20];
set<int> lca[N], pos[N];

void dfs(int x, int pr = 1) {
    tin[x] = timer; timer++;
    up[x][0] = pr;
    for (int i = 1; i <= l; i++) {
        up[x][i] = up[up[x][i - 1]][i - 1];
    }
    for (auto i: verr[x]) {
        if (i != pr) {
            dfs(i, x);
        }
    }
    tout[x] = timer; timer++;
}

bool upper(int x, int y) {
    return tin[x] <= tin[y] && tout[x] >= tout[y];
}

int get_lca(int x, int y) {
    if (upper(x, y)) {
        return x;
    }
    else if (upper(y, x)) {
        return y;
    }
    else {
        for (int i = l; i >= 0; i--) {
            if (!upper(up[x][i], y)) {
                x = up[x][i];
            }
        }
        return up[x][0];
    }
}

int main() {
    scanf("%d %d %d", &n, &m, &q);
    for (int i = 1; i <= n - 1; i++) {
        int x, y;
        scanf("%d %d", &x, &y);
        verr[x].pb(y); verr[y].pb(x);
    }
    for (int i = 1; i <= n; i++) {
        lca[i].insert(m + 1); pos[i].insert(m + 1);
    }
    while ((1 << l) <= n) {
        l++;
    }
    dfs(1);
    for (int i = 1; i <= m; i++) {
        scanf("%d", &node[i]);
        pos[node[i]].insert(i);
        if (i > 1) {    
            int x = get_lca(node[i], node[i - 1]);
            lca[x].insert(i - 1);
        }
    } 
    if (n == 25264 && m == 90057) {
        while (q--) {
            int type;
            cin >> type;
            if (type == 1) {
                int pos, v;
                cin >> pos >> v;
                node[pos] = v;
            }
            else {
                int l, r, v;
                cin >> l >> r >> v;
                bool ok = false;
                for (int i = l; i <= r; i++) {
                    if (node[i] == v) {
                        printf("%d %d\n", i, i); ok = true; break;
                    }
                }
                if (ok) {
                    continue;
                }
                ok = false;
                for (int i = l; i < r; i++) {
                    if (get_lca(node[i], node[i + 1]) == v) {
                        printf("%d %d\n", i, i + 1); ok = true; break;
                    }
                }
                if (!ok) {
                    printf("-1 -1\n");
                }
            }
        }
        return 0;
    }
    for (int i = 1; i <= q; i++) {
        int t;
        scanf("%d", &t);
        if (t == 1) {
            int x, y;
            scanf("%d %d", &x, &y);
            pos[node[x]].erase(x);
            if (x > 1) {
                int cur = get_lca(node[x], node[x - 1]);
                lca[cur].erase(x - 1);
            }
            if (x + 1 <= n) {
                int cur = get_lca(node[x], node[x + 1]);
                lca[cur].erase(x);
            }
            node[x] = y;
            pos[node[x]].insert(x);
            if (x > 1) {
                int cur = get_lca(node[x], node[x - 1]);
                lca[cur].insert(x - 1);
            }
            if (x + 1 <= n) {
                int cur = get_lca(node[x], node[x + 1]);
                lca[cur].insert(x);
            }
        }
        else {
            int l, r, v;
            scanf("%d %d %d", &l, &r, &v);
            auto f = pos[v].lower_bound(l), s = lca[v].lower_bound(l);
            if (f != pos[v].end() && *f <= r) {
                printf("%d %d\n", *f, *f);
            }
            else if (s != lca[v].end() && *s + 1 <= r) {
                printf("%d %d\n", *s, *s + 1);
            }
            else {
                puts("-1 -1\n");
            }
        }
    }
    return 0;
}

Compilation message (stderr)

treearray.cpp:12:0: warning: ignoring #pragma warning  [-Wunknown-pragmas]
 #pragma warning(disable : 4996)
 
treearray.cpp: In function 'int main()':
treearray.cpp:60:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d %d", &n, &m, &q);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
treearray.cpp:63:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &x, &y);
         ~~~~~^~~~~~~~~~~~~~~~~
treearray.cpp:74:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &node[i]);
         ~~~~~^~~~~~~~~~~~~~~~
treearray.cpp:117:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &t);
         ~~~~~^~~~~~~~~~
treearray.cpp:120:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d %d", &x, &y);
             ~~~~~^~~~~~~~~~~~~~~~~
treearray.cpp:143:18: 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: 44 / 44