Submission #139888

#	Time	Username	Problem	Language	Result	Execution time	Memory
139888		Plurm	Horses (IOI15_horses)	C++11	100 / 100	625 ms	71164 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>
using namespace std;
 
const int MOD = 1e9+7;
long double seg1[1048576]; // Sum of log2s
long double seg2[1048576]; // log2(Answer)
int seg3[1048576]; // Range product query
int seg4[1048576]; // Real Answer
int lb[1048576];
int rb[1048576];
int rx[500005];
int ry[500005];

void build(int c, int l, int r){
    lb[c] = l;
    rb[c] = r;
    if(l == r){
        seg1[c] = log2l(rx[l]);
        seg2[c] = log2l(rx[l]) + log2l(ry[l]);
        seg3[c] = rx[l];
        seg4[c] = (1ll * rx[l] * ry[l]) % MOD;
        return;
    }
    int k = (l + r)/2;
    build(2*c,l,k);
    build(2*c+1,k+1,r);
    seg1[c] = seg1[2*c] + seg1[2*c+1];
    seg3[c] = (1ll * seg3[2*c] * seg3[2*c+1]) % MOD;
    if(seg2[2*c] > seg2[2*c+1] + seg1[2*c]){
        seg2[c] = seg2[2*c];
        seg4[c] = seg4[2*c];
    }else{
        seg2[c] = seg2[2*c+1] + seg1[2*c];
        seg4[c] = (1ll * seg4[2*c+1] * seg3[2*c]) % MOD;
    }
}

void update(int c, int idx){
    if(lb[c] == rb[c]){
        seg1[c] = log2l(rx[idx]);
        seg2[c] = log2l(rx[idx]) + log2l(ry[idx]);
        seg3[c] = rx[idx];
        seg4[c] = (1ll * rx[idx] * ry[idx]) % MOD;
        return;
    }
    int k = (lb[c] + rb[c])/2;
    if(idx <= k) update(2*c, idx);
    else update(2*c+1, idx);
    seg1[c] = seg1[2*c] + seg1[2*c+1];
    seg3[c] = (1ll * seg3[2*c] * seg3[2*c+1]) % MOD;
    if(seg2[2*c] > seg2[2*c+1] + seg1[2*c]){
        seg2[c] = seg2[2*c];
        seg4[c] = seg4[2*c];
    }else{
        seg2[c] = seg2[2*c+1] + seg1[2*c];
        seg4[c] = (1ll * seg4[2*c+1] * seg3[2*c]) % MOD;
    }
}

int init(int N, int X[], int Y[]) {
    for(int i = 0; i < N; i++){
        rx[i] = X[i];
        ry[i] = Y[i];
    }
    build(1,0,N-1);
	return seg4[1];
}
 
int updateX(int pos, int val) {
    rx[pos] = val;
    update(1, pos);
    return seg4[1];
}
 
int updateY(int pos, int val) {
    ry[pos] = val;
    update(1, pos);
    return seg4[1];
}

Compilation message (stderr)

horses.cpp: In function 'void build(int, int, int)':
horses.cpp:22:41: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
         seg4[c] = (1ll * rx[l] * ry[l]) % MOD;
                   ~~~~~~~~~~~~~~~~~~~~~~^~~~~
horses.cpp:29:47: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
     seg3[c] = (1ll * seg3[2*c] * seg3[2*c+1]) % MOD;
               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
horses.cpp:35:51: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
         seg4[c] = (1ll * seg4[2*c+1] * seg3[2*c]) % MOD;
                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
horses.cpp: In function 'void update(int, int)':
horses.cpp:44:45: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
         seg4[c] = (1ll * rx[idx] * ry[idx]) % MOD;
                   ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
horses.cpp:51:47: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
     seg3[c] = (1ll * seg3[2*c] * seg3[2*c+1]) % MOD;
               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
horses.cpp:57:51: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
         seg4[c] = (1ll * seg4[2*c+1] * seg3[2*c]) % MOD;
                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~

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