Submission #139552

#	Time	Username	Problem	Language	Result	Execution time	Memory
139552		Plurm	Horses (IOI15_horses)	C++11	17 / 100	539 ms	115672 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>
using namespace std;

multimap<long double, int> mm;
const int MOD = 1e9+7;
long double FT1[500005];
int FT2[500005];
int modpow(int base, int expo){
    if(expo == 0) return 1;
    int res = modpow(base, expo/2);
    if(expo % 2 == 0){
        return (1ll * res * res) % MOD;
    }else{
        return 1ll * ((1ll * res * res) % MOD) * base % MOD;
    }
}
int invmod(int x){
    return modpow(x, MOD-2);
}
void sub(int idx, int amt){
    idx++;
    while(idx < 500005){
        FT1[idx] -= log2l(amt);
        FT2[idx] = (1ll * FT2[idx] * invmod(amt)) % MOD;
        idx += idx & -idx;
    }
}
void add(int idx, int amt){
    idx++;
    while(idx < 500005){
        FT1[idx] += log2l(amt);
        FT2[idx] = (1ll * FT2[idx] * amt) % MOD;
        idx += idx & -idx;
    }
}
long double sum1(int idx){
    idx++;
    long double ret = 0;
    while(idx > 0){
        ret += FT1[idx];
        idx -= idx & -idx;
    }
    return ret;
}
int sum2(int idx){
    idx++;
    int ret = 1;
    while(idx > 0){
        ret = (1ll * ret * FT2[idx]) % MOD;
        idx -= idx & -idx;
    }
    return ret;
}
int rx[500005];
int ry[500005];

int answer(){
    return mm.rbegin()->second;
}

int init(int N, int X[], int Y[]) {
    for(int i = 0; i < N; i++){
        rx[i] = X[i];
        ry[i] = Y[i];
    }
    for(int i = 0; i < 500005; i++) FT2[i] = 1;
    for(int i = 0; i < N; i++){
        add(i, X[i]);
    }
    for(int i = 0; i < N; i++){
        mm.insert(make_pair(sum1(i) + log2l(Y[i]), (int)((1ll * sum2(i) * Y[i]) % MOD)));
    }
	return answer();
}

int updateX(int pos, int val) {
    mm.erase(mm.find(sum1(pos) + log2l(ry[pos])));
    sub(pos, rx[pos]);
    add(pos, val);
    rx[pos] = val;
    mm.insert(make_pair(sum1(pos) + log2l(ry[pos]), (int)((1ll * sum2(pos) * ry[pos]) % MOD)));
	return answer();
}

int updateY(int pos, int val) {
    mm.erase(mm.find(sum1(pos) + log2l(ry[pos])));
    ry[pos] = val;
    mm.insert(make_pair(sum1(pos) + log2l(ry[pos]), (int)((1ll * sum2(pos) * ry[pos]) % MOD)));
	return answer();
}

Compilation message (stderr)

horses.cpp: In function 'int modpow(int, int)':
horses.cpp:13:34: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
         return (1ll * res * res) % MOD;
                ~~~~~~~~~~~~~~~~~~^~~~~
horses.cpp:15:55: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
         return 1ll * ((1ll * res * res) % MOD) * base % MOD;
                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
horses.cpp: In function 'void sub(int, int)':
horses.cpp:25:51: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
         FT2[idx] = (1ll * FT2[idx] * invmod(amt)) % MOD;
                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
horses.cpp: In function 'void add(int, int)':
horses.cpp:33:43: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
         FT2[idx] = (1ll * FT2[idx] * amt) % MOD;
                    ~~~~~~~~~~~~~~~~~~~~~~~^~~~~
horses.cpp: In function 'int sum2(int)':
horses.cpp:50:38: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
         ret = (1ll * ret * FT2[idx]) % MOD;
               ~~~~~~~~~~~~~~~~~~~~~~~^~~~~

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