Submission #62292

#	Time	Username	Problem	Language	Result	Execution time	Memory
62292		Tenuun	Horses (IOI15_horses)	C++17	17 / 100	1575 ms	37948 KiB

horses

#include<bits/stdc++.h>
#define mod 1000000007
#define ll long long
using namespace std;

int n, tr[2000000], id[500001];
ll now=1;
vector<int>x, y;
set<int>a;
void pre(){
	int last=-1;
	a.insert(-1);
	a.insert(0);
	for(int i=1; i<n; i++){
		if(x[i]>1){
			a.insert(i);
		}
	}
}

void build(int ind, int l, int r){
	if(l==r){
		tr[ind]=y[l];
		id[l]=ind;
		return;
	}
	build(ind*2, l, (l+r)/2);
	build(ind*2+1, (l+r)/2+1, r);
	tr[ind]=max(tr[ind*2], tr[ind*2+1]);
}

ll rmq(int ind, int l, int r, int L, int R){
	if(l==L && r==R) return tr[ind];
	int m=(l+r)/2;
	if(R<=m) return rmq(ind*2, l, m, L, R);
	else if(L>m) return rmq(ind*2+1, m+1, r, L, R);
	else{
		return max(rmq(ind*2, l, m, L, m), rmq(ind*2+1, m+1, r, m+1, R));
	}
}

ll find(){
	int last=a.size()-1, ind=a.size();
	ll ans=1;
	ll now=rmq(1, 0, n-1, *--a.end(), n-1);
	set<int>::iterator it;
	for(it=prev(a.end()); it!=a.begin() && now<mod; it--){
		if(now*x[*it]>mod) break;
		now*=x[*it];
	}
	ans=now;
	now/=rmq(1, 0, n-1, *--a.end(), n-1);
	for(set<int>::iterator tmp=prev((prev(a.end()))); tmp!=prev(it) && tmp!=a.begin(); tmp--){
		now/=x[*next(tmp)];
		ans=max(ans, now*rmq(1, 0, n-1, *tmp, *next(tmp)-1));
	}
	for(; it!=a.begin(); it--){
		ans*=x[*it];
		ans%=mod;
	}
	return ans;
}

int init(int N, int X[], int Y[]) {
	n=N;
	for(int i=0; i<n; i++) {x.push_back(X[i]); y.push_back(Y[i]);}
	pre();
	build(1, 0, n-1);
	return find();
}

int updateX(int pos, int val){
	if(x[pos]==1 && val==1) return find();
	if(x[pos]>1 && val>1){
		x[pos]=val;
		///now/x[pos]*val;
		return find();
	}
	if(x[pos]==1){
		a.insert(pos);
		x[pos]=val;
	}
	else{
		a.erase(a.find(pos));
		x[pos]=1;
	}
	return find();
}

int updateY(int pos, int val){
	tr[id[pos]]=val;
	return find();
}

Compilation message (stderr)

horses.cpp: In function 'void pre()':
horses.cpp:11:6: warning: unused variable 'last' [-Wunused-variable]
  int last=-1;
      ^~~~
horses.cpp: In function 'long long int find()':
horses.cpp:43:19: warning: conversion to 'int' from 'std::set<int>::size_type {aka long unsigned int}' may alter its value [-Wconversion]
  int last=a.size()-1, ind=a.size();
           ~~~~~~~~^~
horses.cpp:43:33: warning: conversion to 'int' from 'std::set<int>::size_type {aka long unsigned int}' may alter its value [-Wconversion]
  int last=a.size()-1, ind=a.size();
                           ~~~~~~^~
horses.cpp:45:5: warning: declaration of 'now' shadows a global declaration [-Wshadow]
  ll now=rmq(1, 0, n-1, *--a.end(), n-1);
     ^~~
horses.cpp:7:4: note: shadowed declaration is here
 ll now=1;
    ^~~
horses.cpp:43:6: warning: unused variable 'last' [-Wunused-variable]
  int last=a.size()-1, ind=a.size();
      ^~~~
horses.cpp:43:23: warning: unused variable 'ind' [-Wunused-variable]
  int last=a.size()-1, ind=a.size();
                       ^~~
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:69:13: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
  return find();
         ~~~~^~
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:73:37: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
  if(x[pos]==1 && val==1) return find();
                                 ~~~~^~
horses.cpp:77:14: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
   return find();
          ~~~~^~
horses.cpp:87:13: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
  return find();
         ~~~~^~
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:92:13: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
  return find();
         ~~~~^~

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