제출 #1241001

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1241001		edga1	말 (IOI15_horses)	C++20	17 / 100	59 ms	9032 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int MOD=1e9+7, MAXN=5e5+5;
int x[MAXN],y[MAXN],n,preh=1;

inline int times(int a, int b){return 1LL*a*b%MOD;}

void pre(){
    for(int i=0; i<=n-30; i++) preh=times(preh,x[i]);
}

int modpow(int a, int p){
    int r=1;
    while(p>0){
        if(p&1) r=times(r,a);
        a=times(a,a);
        p>>=1;
    }
    return r;
}

int inv(int a){
    return modpow(a,MOD-2);
}

int calculate(){
    ll besti=n-1,tot=x[n-1];
	for(int i=n-2; i>=max(0,n-30); i--){
        if(y[i]>tot*y[besti]){
            besti=i;
            tot=1;
        }
        tot*=x[i];
        if(tot>=1e9) break;
	}
	int h=preh;
	for(int i=max(0,n-29); i<=besti; i++){
        h=times(h,x[i]);
	}
	return times(h,y[besti]);
}

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];
	}
	pre();
	return calculate();
}

int updateX(int pos, int val) {
    x[pos]=val;
    if(pos<=n-30){
        preh=times(preh,times(val,inv(val)));
    }
	return calculate();
}

int updateY(int pos, int val) {
    y[pos]=val;
	return calculate();
}

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