Submission #1241028

#	Time	Username	Problem	Language	Result	Execution time	Memory
1241028		edga1	Horses (IOI15_horses)	C++20	37 / 100	123 ms	13336 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,st[1050000];

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

void update(int x, int xl, int xr, int pos, int val){
    if(xl==xr){
        st[x]=val;
        return;
    }
    int mid=(xl+xr)/2;
    if(pos<=mid) update(x*2+1,xl,mid,pos,val);
    else update(x*2+2,mid+1,xr,pos,val);
    st[x]=times(st[x*2+1],st[x*2+2]);
    return;
}

int sum(int x, int xl, int xr, int l, int r){
    if(xl>=l && xr<=r) return st[x];
    if(xl>r || xr<l) return 1;
    int mid=(xl+xr)/2;
    return times(sum(x*2+1,xl,mid,l,r),sum(x*2+2,mid+1,xr,l,r));
}

int findbesti(){
    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;
	}
	return besti;
}

int calculate(){
    int besti=findbesti();
	return times(sum(0,0,n-1,0,besti),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];
        update(0,0,n-1,i,x[i]);
	}
	return calculate();
}

int updateX(int pos, int val) {
    x[pos]=val;
    update(0,0,n-1,pos,val);
	return calculate();
}

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

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