Submission #760379

#	Time	Username	Problem	Language	Result	Execution time	Memory
760379		GrindMachine	Horses (IOI15_horses)	C++17	0 / 100	307 ms	53372 KiB

horses

// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

sell at exactly 1 place

*/

const int MOD = 1e9 + 7;
const int N = 5e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

#include "horses.h"

template<typename T>
struct segtree1 {
    // https://codeforces.com/blog/entry/18051
 
    /*=======================================================*/
 
    struct data {
    	ll a;
    };
 
    data neutral = {1};
 
    data merge(data &left, data &right) {
    	data curr;
    	curr.a = left.a * right.a % MOD;
    	return curr;
    }
 
    void create(int i, T v) {
    	tr[i].a = v;
    }
 
    void modify(int i, T v) {
    	tr[i].a = v;
    }
 
    /*=======================================================*/
 
    int n;
    vector<data> tr;
 
    segtree1() {
 
    }
 
    segtree1(int siz) {
        init(siz);
    }
 
    void init(int siz) {
        n = siz;
        tr.assign(2 * n, neutral);
    }
 
    void build(vector<T> &a, int siz) {
        rep(i, siz) create(i + n, a[i]);
        rev(i, n - 1, 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
    }
 
    void pupd(int i, T v) {
        modify(i + n, v);
        for (i = (i + n) >> 1; i; i >>= 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
    }
 
    data query(int l, int r) {
        data resl = neutral, resr = neutral;
 
        for (l += n, r += n; l <= r; l >>= 1, r >>= 1) {
            if (l & 1) resl = merge(resl, tr[l++]);
            if (!(r & 1)) resr = merge(tr[r--], resr);
        }
 
        return merge(resl, resr);
    }
};

template<typename T>
struct segtree2 {
    // https://codeforces.com/blog/entry/18051

    /*=======================================================*/

    struct data {
    	ll a;
    };

    data neutral = {0};

    data merge(data &left, data &right) {
    	data curr;
    	curr.a = max(left.a,right.a);
    	return curr;
    }

    void create(int i, T v) {
    	tr[i].a = v;
    }

    void modify(int i, T v) {
    	tr[i].a = v;
    }

    /*=======================================================*/

    int n;
    vector<data> tr;

    segtree2() {

    }

    segtree2(int siz) {
        init(siz);
    }

    void init(int siz) {
        n = siz;
        tr.assign(2 * n, neutral);
    }

    void build(vector<T> &a, int siz) {
        rep(i, siz) create(i + n, a[i]);
        rev(i, n - 1, 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
    }

    void pupd(int i, T v) {
        modify(i + n, v);
        for (i = (i + n) >> 1; i; i >>= 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
    }

    data query(int l, int r) {
        data resl = neutral, resr = neutral;

        for (l += n, r += n; l <= r; l >>= 1, r >>= 1) {
            if (l & 1) resl = merge(resl, tr[l++]);
            if (!(r & 1)) resr = merge(tr[r--], resr);
        }

        return merge(resl, resr);
    }
};

ll n;
vector<ll> a(N), b(N);
set<ll> active;
segtree1<ll> st_prod(N);
segtree2<ll> st_max(N);

int get_ans(){
	// {
	// 	ll ans = 0;
	// 	ll curr = 1;
	// 	rep(i,n){
	// 		curr *= a[i];
	// 		amax(ans, curr * b[i]);
	// 	}

	// 	return ans;
	// }

	ll prod = 1;
	vector<ll> points;
	points.pb(n);

	bool big = false;

	for(auto it = active.rbegin(); it != active.rend(); ++it){
		ll pos = *it;
		prod *= a[pos];
		points.pb(pos);

		if(prod > inf1){
			big = true;
			break;
		}
	}

	if(!big and points.back() != 0){
		points.pb(0);
	}

	reverse(all(points));

	ll befprod = st_prod.query(0,points.front()-1).a;
	__int128 curr = 1;
	__int128 best = 0;

	rep(i,sz(points)-1){
		curr *= a[i];
		ll l = points[i], r = points[i+1]-1;
		ll mxb = st_max.query(l,r).a;
		amax(best, curr * mxb);
	}

	ll ans = (best % MOD) * befprod % MOD;
	return ans;
}

int init(int n_, int X[], int Y[]) {
	n = n_;
	rep(i,n) a[i] = X[i], b[i] = Y[i];

	rep(i,n){
		if(a[i] > 1){
			active.insert(i);
		}

		st_prod.pupd(i,a[i]);
		st_max.pupd(i,b[i]);
	}

	return get_ans();
}

int updateX(int pos, int val) {
	if(a[pos] > 1){
		active.erase(pos);
	}

	a[pos] = val;
	st_prod.pupd(pos,val);

	if(a[pos] > 1){
		active.insert(pos);
	}

	return get_ans();	
}

int updateY(int pos, int val) {
	b[pos] = val;
	st_max.pupd(pos,val);
	return get_ans();
}

Compilation message (stderr)

horses.cpp: In function 'int get_ans()':
horses.cpp:237:45: warning: conversion from '__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type' {aka 'long long int'} to 'int' may change value [-Wconversion]
  237 |  ll befprod = st_prod.query(0,points.front()-1).a;
      |                               ~~~~~~~~~~~~~~^~
horses.cpp:30:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 | #define rep(i, n) for(int i = 0; i < n; ++i)
......
  241 |  rep(i,sz(points)-1){
      |      ~~~~~~~~~~~~~~                 
horses.cpp:241:2: note: in expansion of macro 'rep'
  241 |  rep(i,sz(points)-1){
      |  ^~~
horses.cpp:244:25: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
  244 |   ll mxb = st_max.query(l,r).a;
      |                         ^
horses.cpp:244:27: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
  244 |   ll mxb = st_max.query(l,r).a;
      |                           ^
horses.cpp:248:34: warning: conversion from '__int128' to 'll' {aka 'long long int'} may change value [-Wconversion]
  248 |  ll ans = (best % MOD) * befprod % MOD;
      |           ~~~~~~~~~~~~~~~~~~~~~~~^~~~~
horses.cpp:249:9: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
  249 |  return ans;
      |         ^~~

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