Submission #310670

#	Time	Username	Problem	Language	Result	Execution time	Memory
310670		talant117408	Horses (IOI15_horses)	C++17	100 / 100	205 ms	39036 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef pair <int, int> pii;
 
#define precision(n) fixed << setprecision(n)
#define pb push_back
#define ub upper_bound
#define lb lower_bound
#define mp make_pair
#define eps (double)1e-9
#define PI 2*acos(0.0)
#define endl "\n"
#define sz(v) (int)(v).size()
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define do_not_disturb ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);

const ll mod = 1e9+7;
const int mxn = 5e5+7;
int x[mxn], y[mxn];
int n;

struct Node{
    int x, y;
    double _x, _y;
};

int mult(int a, int b){
    return (ll(a)*ll(b))%mod;
}

Node combine(Node a, Node b){
    Node res;
    
    if(a._y > a._x+b._y){
        res.y = a.y;
        res._y = a._y;
    }
    else{
        res.y = mult(a.x, b.y);
        res._y = a._x+b._y;
    }
    res.x = mult(a.x, b.x);
    res._x = a._x+b._x;
    
    return res;
}

struct Tree{
    Node tree[mxn*3];
    
    void build(int v, int l, int r){
        if(l == r){
            tree[v].x = x[l];
            tree[v].y = mult(y[l], x[l]);
            tree[v]._x = log2(x[l]);
            tree[v]._y = log2(y[l])+log2(x[l]);
            return;
        }
        int mid = (l+r) >> 1;
        build(v<<1, l, mid);
        build((v<<1)+1, mid+1, r);
        tree[v] = combine(tree[v<<1], tree[(v<<1)+1]);
    }
    
    void update(int v, int l, int r, int pos){
        if(pos == l && r == l){
            tree[v].x = x[l];
            tree[v].y = mult(y[l], x[l]);
            tree[v]._x = log2(x[l]);
            tree[v]._y = log2(y[l])+log2(x[l]);
            return;
        }
        int mid = (l+r) >> 1;
        if(pos <= mid){
            update(v<<1, l, mid, pos);
        }
        else{
            update((v<<1)+1, mid+1, r, pos);
        }
        tree[v] = combine(tree[v<<1], tree[(v<<1)+1]);
    }
    
    int query(){
        return tree[1].y;
    }
} tree;

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];
    }
    tree.build(1, 0, n-1);
    
    return tree.query();
}

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

int updateY(int pos, int val){
    y[pos] = val;
    tree.update(1, 0, n-1, pos);
    
	return tree.query();
}

/*
3
2 1 3
3 4 1
1
2 1 2

8
6
*/

Compilation message (stderr)

horses.cpp: In function 'int mult(int, int)':
horses.cpp:33:25: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   33 |     return (ll(a)*ll(b))%mod;
      |            ~~~~~~~~~~~~~^~~~

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