Submission #259309

#	Time	Username	Problem	Language	Result	Execution time	Memory
259309		IOrtroiii	Horses (IOI15_horses)	C++14	0 / 100	374 ms	59384 KiB

horses

#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ld = long double;

const int MX = 500500;

int N;
int X[MX], Y[MX];

namespace searcher {

pair<ld, int> best[MX << 1];
ld sum[MX << 1];

void pop(int v) {
   best[v] = max(best[v << 1], make_pair(best[v << 1 | 1].first + sum[v << 1], best[v].second));
   sum[v] = sum[v << 1] + sum[v << 1 | 1];
}

void modify(int p) {
   p += N;
   best[p] = make_pair(log(X[p - N]) + log(Y[p - N]), p - N);
   sum[p] = log(X[p - N]);
   for (p >>= 1; p > 0; p >>= 1) {
      pop(p);
   }
}

};

namespace calculator {
static const int MOD = 1000000007;

int mult(int x, int y) { return ll(x) * y % MOD; }
int st[MX << 1];

void modify(int p) {
   p += N;
   st[p] = X[p - N];
   for (p >>= 1; p > 0; p >>= 1) {
      st[p] = mult(st[p << 1], st[p << 1 | 1]);
   }
}

int query(int p) {
   int ans = Y[p];
   for (int l = N, r = p + N; l <= r; l >>= 1, r >>= 1) {
      if (l & 1) ans = mult(ans, st[l++]);
      if (!(r & 1)) ans = mult(ans, st[r--]);
   }
   return ans;
}

};

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];
   for (int i = 0; i < N; ++i) {
      searcher::modify(i);
      calculator::modify(i);
   }
   return calculator::query(searcher::best[1].second);
}

int updateX(int pos, int val) {
   X[pos] = val;
   searcher::modify(pos);
   calculator::modify(pos);
   return calculator::query(searcher::best[1].second);
}

int updateY(int pos, int val) {
   Y[pos] = val;
   searcher::modify(pos);
   calculator::modify(pos);
   return calculator::query(searcher::best[1].second);
}

Compilation message (stderr)

horses.cpp: In function 'int calculator::mult(int, int)':
horses.cpp:37:43: warning: conversion to 'int' from 'll {aka long long int}' may alter its value [-Wconversion]
 int mult(int x, int y) { return ll(x) * y % MOD; }
                                 ~~~~~~~~~~^~~~~

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