Submission #1159810

#	Time	Username	Problem	Language	Result	Execution time	Memory
1159810		YSH2020	Specijacija (COCI20_specijacija)	C++20	0 / 110	508 ms	1114112 KiB

Main

#include <bits/stdc++.h>
using namespace std;
int depth(int x) {
	if ((int)(pow(8*x+1, 0.5)+1)/2 == (pow(8*x+1, 0.5)+1)/2) return (pow(8*x+1, 0.5)+1)/2-1;
	else return (int)(pow(8*x+1, 0.5)+1)/2;
}
//time to deal with binary lifting :(
signed main() {
	int n; cin >> n;
	int q; cin >> q;
	int t; cin >> t;
	int a[n+1];
	for (int i = 1; i < n+1; i++) {
		int x; cin >> x;
		a[i] = x-((i-1)*i)/2;
	}
	pair<int,int> par[n+2][n+2][15]; for (int i = 0; i < n+2; i++) for (int j = 0; j < n+2; j++) par[i][j][0] = {0,0};
	for (int i = 2; i < n+2; i++) {
		for (int j = 1; j <= i; j++) {
			if (j > a[i-1]) par[i][j][0] = {i-1, j-1};
			else par[i][j][0] = {i-1,j};
		}
	}
	for (int i = 1; i < 15; i++) {
		for (int j = 2; j < n+2; j++) {
			for (int k = 1; k <= j; k++) {
				par[j][k][i] = par[par[j][k][i-1].first][par[j][k][i-1].second][i-1];
			}
		}
	}
	while (q--) {
		int x, y; cin >> x >> y;
		//first check for depth
		if (y > x) swap(x, y);
		pair<int,int> cox, coy;
		cox = {depth(x), x-((depth(x)-1)*depth(x))/2};
		coy = {depth(y), y-((depth(y)-1)*depth(y))/2};

		int tmp = depth(x)-depth(y);
		//now lift x until its the same depth :)
		for (int i = 14; i >= 0; i--) {
			if ((tmp&(1<<i)) > 0) cox = par[cox.first][cox.second][i];
		}
		//now they are the same depth. now we can do some lca :)
		if (cox == coy) {
			cout << ((cox.first-1)*cox.first)/2+cox.second << '\n';
		}
		else {
			for (int i = 14; i >= 0; i--) {
				auto tmp1 = par[cox.first][cox.second][i];
				auto tmp2 = par[coy.first][coy.second][i];
				if (tmp1.first != tmp2.first or tmp1.second != tmp2.second) {
					cox = tmp1;
					coy = tmp2;
				}
			}
			cox = par[cox.first][cox.second][0];
			cout << ((cox.first-1)*cox.first)/2+cox.second << '\n';
		}
	}
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 30
• Subtask 4: 0 / 60