Submission #1312850

#	Time	Username	Problem	Language	Result	Execution time	Memory
1312850		nikaa123	Horses (IOI15_horses)	C++20	17 / 100	152 ms	26612 KiB

horses

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

const int inf = INT_MAX;
const int mod = 1000000007;
const int S = 5e5+5;

int n;
int x[S],y[S];
int pref[S];
int t[4*S];
int lazy[4*S];


void applay(int x, int val) {
	t[x] = (t[x] * val) % mod;
	lazy[x] = (lazy[x] * val) % mod;
}

void push(int x) {
	if (lazy[x] != 1) {
		applay(x*2,lazy[x]);
		applay(x*2+1,lazy[x]);
		lazy[x] = 1;
	}
}

void update(int node, int l, int r, int L, int R, int val) {
	if (r < L || l > R) return;
	if (l >= L && r <= R) {
		applay(node,val);
		return;
	}
	push(node);
	int mid = (l+r)/2;
	update(node*2,l,mid,L,R,val);
	update(node*2+1,mid+1,r,L,R,val);
	t[node] = max(t[node*2],t[node*2+1]);
}

int getans(int node, int l, int r, int L, int R) {
	if (r < L || l > R) return -inf;
	if (l >= L && r <= R) return t[node];
	push(node);
	int mid = (l+r)/2;
	return max(getans(node*2,l,mid,L,R),getans(node*2+1,mid+1,r,L,R));
}

int inv(int x, int k = mod - 2) {
	int res = 1;
	while (k) {
		if (k&1) {
			res = (res * x) % mod;
		}
		x = (x * x) % mod;
		k >>= 1;
	}
	return res;
}

int init(int N, int X[], int Y[]) {
	n = N;
	for (int i = 0; i < n; i++) {
		x[i] = X[i];
		y[i] = Y[i];
	}
	pref[0] = X[0];
	for (int i = 1; i < n; i++) {
		pref[i] = (pref[i-1] * x[i]) % mod;
	}
	for (int i = 0; i < n; i++) {
		pref[i] = (pref[i] * y[i]) % mod;
	}
	for (int i = 1; i <= 4*n; i++) {
		lazy[i] = 1;
		t[i] = 1;
	}
	for (int i = 1; i <= n; i++) {
		update(1,1,n,i,i,pref[i-1]);
	}
	return getans(1,1,n,1,n);
}

int updateX(int pos, int val) {	
	update(1,1,n,pos+1,n,inv(x[pos]));
	x[pos] = val;
	update(1,1,n,pos+1,n,x[pos]);
	return getans(1,1,n,1,n);
}

int updateY(int pos, int val) {
	update(1,1,n,pos+1,pos+1,inv(y[pos]));
	y[pos] = val;
	update(1,1,n,pos+1,pos+1,y[pos]);
	return getans(1,1,n,1,n);
}

• Subtask 1: 17 / 17
• Subtask 2: 0 / 17
• Subtask 3: 0 / 20
• Subtask 4: 0 / 23
• Subtask 5: 0 / 23