Submission #1302281

#	Time	Username	Problem	Language	Result	Execution time	Memory
1302281		nicolo_010	말 (IOI15_horses)	C++20	17 / 100	1597 ms	36852 KiB

horses

#include <bits/stdc++.h>
#include "horses.h"
using namespace std;
using ll = long long;
using pii = pair<int, int>;
const int MOD = 1e9+7;

const ll INF = 1e18;

vector<ll> x;
vector<ll> y;
int n;

struct SegTree {
	vector<ll> tree;
	SegTree() {
	}

	void init(int m) {
		tree.assign(4*m, 0);
	}

	void query(int p, int l, int r, int i, int x) {
		if (l > i || r < i) return;
		if (l==r) {
			tree[p] = x;
		}
		else {
			int m = (l+r)/2;
			query(2*p, l, m, i, x);
			query(2*p+1, m+1, r, i, x);
			ll i1 = tree[2*p];
			ll i2 = tree[2*p+1];
			tree[p] = (i1*i2) % MOD;
		}
	}
	ll rsq(int p, int l, int r, int i, int j) {
		if (l > j || r < i) return 1;
		if (i <= l && r <= j) {
			return tree[p];
		}
		else {
			int m = (l+r)/2;
			ll i1 = rsq(2*p, l, m, i, j);
			ll i2 = rsq(2*p+1, m+1, r, i, j);
			return (i1*i2)%MOD;
		}
	}
};
SegTree st;

ll compute(vector<ll> a, vector<ll> b) {
	int m = a.size();
	int beg = max(0, m-30);
	int idx=beg;
	ll prod=1;
	bool moduled = false;
	for (int i=beg+1; i<m; i++) {
		ll y0 = b[idx];
		ll y1 = b[i];
		prod *= x[i];
		if (prod >= MOD) {
			moduled = true;
			prod %= MOD;
		}
		if (moduled) {
			//Se que y[i] <= y[j]*prod
			//Conviene j
			idx = i;
			moduled = 0;
			prod = 1;
		}
		else {
			if (prod*y1 >= y0) {
				idx = i;
				prod = 1;
				moduled = false;
			}
		}
	}
	prod = st.rsq(1, 0, n-1, 0, idx);
	return (prod*y[idx])%MOD;
}

int init(int N, int* a, int* b) {
	n = N;
	x.assign(n, 0);
	y.assign(n, 0);
	for (int i=0; i<n; i++) {
		x[i] = a[i];
		y[i] = b[i];
	}
	st.init(n);
	for (int i=0; i<n; i++) {
		st.query(1, 0, n-1, i, x[i]);
	}
	return compute(x, y);
}

int updateX(int pos, int val) {
	x[pos] = val;
	st.query(1, 0, n-1, pos, val);
	return compute(x, y);
}

int updateY(int pos, int val) {
	y[pos] = val;
	return compute(x, y);
}

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