Submission #935011

#	Time	Username	Problem	Language	Result	Execution time	Memory
935011		PagodePaiva	Horses (IOI15_horses)	C++17	17 / 100	28 ms	16476 KiB

horses

#include <bits/stdc++.h>
#include "horses.h"
#define N 500010

using namespace std;

int n;
long long v[N][2];
long long dp[N];
const int mod = 1e9+7;
long long p = 1;

long long binpow(int a, int b, int m){
	if(b == 0) return 1;
	int t = binpow(a, b/2, m);
	if(b % 2 == 0) return (t*t) % m;
	else return ((((t*t) % m)*a) % m);
}

int solve(){
	if(n >= 40){
		return (p*v[n][1]) % mod;
	}
	else{
		long long aux = 1;
		for(int i = 1;i <= n;i++){
			aux *= v[i][0];
			if(aux > 1e9){
				return (p*v[n][1]) % mod;
			}
		}
	}
	dp[0] = 0;
	long long res = 0;
	for(int i = 1;i <= n;i++){
		dp[i] = 0;
		int prod = 1;
		for(int j = i;j > 0;j--){
			prod *= v[j][0];
			dp[i] = max(dp[i], dp[j-1] + ((prod-1)*v[i][1]));
			res = max(res, dp[j-1] + prod*v[i][1]);
		}
		// cout << dp[i] << ' ';
	}
	return res % mod;
}

int init(int NN, int X[], int Y[]) {
	n = NN;
	for(int i = 1;i <= n;i++){
		v[i][0] = X[i-1];
		p *= v[i][0];
		p %= mod;
		v[i][1] = Y[i-1];
	}
	return solve();
}

int updateX(int pos, int val) {
	p *= binpow(v[pos+1][0], mod-2, mod);	
	p %= mod;
	v[pos+1][0] = val;
	p *= val;
	p %= mod;
	return solve();
}

int updateY(int pos, int val) {
	v[pos+1][1] = val;
	return solve();
}

Compilation message (stderr)

horses.cpp: In function 'long long int binpow(int, int, int)':
horses.cpp:15:16: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   15 |  int t = binpow(a, b/2, m);
      |          ~~~~~~^~~~~~~~~~~
horses.cpp: In function 'int solve()':
horses.cpp:22:22: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   22 |   return (p*v[n][1]) % mod;
      |          ~~~~~~~~~~~~^~~~~
horses.cpp:28:7: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
   28 |    if(aux > 1e9){
      |       ^~~
horses.cpp:29:24: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   29 |     return (p*v[n][1]) % mod;
      |            ~~~~~~~~~~~~^~~~~
horses.cpp:39:9: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   39 |    prod *= v[j][0];
      |    ~~~~~^~~~~~~~~~
horses.cpp:45:13: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   45 |  return res % mod;
      |         ~~~~^~~~~
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:60:24: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   60 |  p *= binpow(v[pos+1][0], mod-2, mod);
      |              ~~~~~~~~~~^

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