Submission #54196

#	Time	Username	Problem	Language	Result	Execution time	Memory
54196		ulna	Birthday gift (IZhO18_treearray)	C++11	100 / 100	1893 ms	98516 KiB

treearray

#pragma GCC optimize ("O3")

#include <bits/stdc++.h>
using namespace std;

// why am I so weak

const int maxn = 2e5;

int n, m, q;
int a[maxn];

vector<int> g[maxn];

#define MAX_LOG 18

int depth[maxn];
int par[MAX_LOG][maxn];

set<int> s[maxn];
set<int> ss[maxn];

void dfs(int v, int par = -1, int d = 0) {
	::par[0][v] = par;
	depth[v] = d;

	for (auto u : g[v]) if (u != par) {
		dfs(u, v, d + 1);
	}
}
inline int lca(int v, int u) {
	if (depth[u] > depth[v]) swap(u, v);

	for (int i = 0; i < MAX_LOG; i++) if (((depth[v] - depth[u]) >> i) & 1) {
		v = par[i][v];
	}

	if (u == v) return u;

	for (int i = MAX_LOG - 1; i >= 0; i--) if (par[i][v] != par[i][u]) {
		v = par[i][v], u = par[i][u];
	}

	return par[0][v];
}
inline void upd(int id, int mode) {
	if (id < 0 || id + 1 >= m) return;

	if (mode == -1) ss[lca(a[id], a[id + 1])].erase(id);
	else ss[lca(a[id], a[id + 1])].insert(id);
}
int main() {
	cin >> n >> m >> q;

	for (int i = 0; i + 1 < n; i++) {
		int x, y;
		scanf("%d %d", &x, &y);
		x--, y--;

		g[x].push_back(y);
		g[y].push_back(x);
	}

	dfs(0);

	for (int i = 0; i + 1 < MAX_LOG; i++) for (int j = 0; j < n; j++) {
		if (par[i][j] < 0) par[i + 1][j] = -1;
		else par[i + 1][j] = par[i][par[i][j]];
	}

	for (int i = 0; i < m; i++) {
		scanf("%d", &a[i]);
		a[i]--;
		s[a[i]].insert(i);
	}

	for (int i = 0; i + 1 < m; i++) {
		ss[lca(a[i], a[i + 1])].insert(i);	
	}

	while (q--) {
		int ope;
		scanf("%d", &ope);

		if (ope == 1) {
			int x, y;
			scanf("%d %d", &x, &y);
			x--, y--;

			s[a[x]].erase(x);

			upd(x, -1);
			upd(x - 1, -1);

			a[x] = y;
			s[a[x]].insert(x);

			upd(x, 1);
			upd(x - 1, 1);
		} else {
			int x, y, z;
			scanf("%d %d %d", &x, &y, &z);
			x--, y--, z--;
			
			auto lb = s[z].lower_bound(x);

			if (lb != s[z].end() && *lb <= y) {
				printf("%d %d\n", *lb + 1, *lb + 1);
				continue;
			}

			lb = ss[z].lower_bound(x);

			if (lb != ss[z].end() && *lb < y) {
				printf("%d %d\n", *lb + 1, *lb + 2);
				continue;
			}

			puts("-1 -1");
		}
	}

	return 0;
}

Compilation message (stderr)

treearray.cpp: In function 'int main()':
treearray.cpp:57:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &x, &y);
   ~~~~~^~~~~~~~~~~~~~~~~
treearray.cpp:72:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a[i]);
   ~~~~~^~~~~~~~~~~~~
treearray.cpp:83:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &ope);
   ~~~~~^~~~~~~~~~~~
treearray.cpp:87:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d %d", &x, &y);
    ~~~~~^~~~~~~~~~~~~~~~~
treearray.cpp:102:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d %d %d", &x, &y, &z);
    ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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