zoukankan      html  css  js  c++  java
  • Codeforces 474 F. Ant colony


    线段树求某一段的GCD.....


    F. Ant colony
    time limit per test
    1 second
    memory limit per test
    256 megabytes
    input
    standard input
    output
    standard output

    Mole is hungry again. He found one ant colony, consisting of n ants, ordered in a row. Each ant i (1 ≤ i ≤ n) has a strength si.

    In order to make his dinner more interesting, Mole organizes a version of «Hunger Games» for the ants. He chooses two numbers l and r(1 ≤ l ≤ r ≤ n) and each pair of ants with indices between l and r (inclusively) will fight. When two ants i and j fight, ant i gets one battle point only if si divides sj (also, ant j gets one battle point only if sj divides si).

    After all fights have been finished, Mole makes the ranking. An ant i, with vi battle points obtained, is going to be freed only if vi = r - l, or in other words only if it took a point in every fight it participated. After that, Mole eats the rest of the ants. Note that there can be many ants freed or even none.

    In order to choose the best sequence, Mole gives you t segments [li, ri] and asks for each of them how many ants is he going to eat if those ants fight.

    Input

    The first line contains one integer n (1 ≤ n ≤ 105), the size of the ant colony.

    The second line contains n integers s1, s2, ..., sn (1 ≤ si ≤ 109), the strengths of the ants.

    The third line contains one integer t (1 ≤ t ≤ 105), the number of test cases.

    Each of the next t lines contains two integers li and ri (1 ≤ li ≤ ri ≤ n), describing one query.

    Output

    Print to the standard output t lines. The i-th line contains number of ants that Mole eats from the segment [li, ri].

    Sample test(s)
    input
    5
    1 3 2 4 2
    4
    1 5
    2 5
    3 5
    4 5
    
    output
    4
    4
    1
    1
    
    Note

    In the first test battle points for each ant are v = [4, 0, 2, 0, 2], so ant number 1 is freed. Mole eats the ants 2345.

    In the second test case battle points are v = [0, 2, 0, 2], so no ant is freed and all of them are eaten by Mole.

    In the third test case battle points are v = [2, 0, 2], so ants number 3 and 5 are freed. Mole eats only the ant 4.

    In the fourth test case battle points are v = [0, 1], so ant number 5 is freed. Mole eats the ant 4.


    #include <iostream>
    #include <cstdio>
    #include <cstring>
    #include <algorithm>
    #include <map>
    #include <vector>
    
    using namespace std;
    
    const int maxn=100100;
    typedef pair<int,int> pII;
    
    pII b[maxn];
    int n,s[maxn];
    int g[maxn<<2];
    
    int gcd(int x,int y)
    {
    	if(x==0) return y;
    	return gcd(y%x,x);
    }
    
    void build(int l,int r,int rt)
    {
    	if(l==r)
    	{
    		g[rt]=s[l];
    		return ;
    	}
    	int mid=(l+r)/2;
    	build(l,mid,rt<<1); build(mid+1,r,rt<<1|1);
    	g[rt]=gcd(g[rt<<1],g[rt<<1|1]);
    }
    
    int query(int L,int R,int l,int r,int rt)
    {
    	if(r<L||l>R) return 0;
    	if(L<=l&&r<=R)
    	{
    		return g[rt];
    	}
    	int mid=(l+r)/2;
    	int u=query(L,R,l,mid,rt<<1);
    	int v=query(L,R,mid+1,r,rt<<1|1);
    	return gcd(u,v);
    }
    
    int main()
    {
    	scanf("%d",&n);
    	for(int i=1;i<=n;i++)
    	{
    		scanf("%d",s+i);
    		b[i]=(make_pair(s[i],i));
    	}
    	sort(b+1,b+1+n);
    	build(1,n,1);
    	int m;
    	scanf("%d",&m);
    	while(m--)
    	{
    		int Left,Right;
    		scanf("%d%d",&Left,&Right);
    		int G=query(Left,Right,1,n,1);
    		int from=lower_bound(b+1,b+n+1,make_pair(G,Left))-(b+1);
    		int to=lower_bound(b+1,b+1+n,make_pair(G,Right+1))-(b+1);
    		printf("%d
    ",(Right-Left+1)-(to-from));
    	}
    	return 0;
    }
    



  • 相关阅读:
    轻松完成mysql4.1与mysql4.0数据库转换备份
    MYSQL数据迁徙tips,ORA00907: missing right parenthesis
    viking病毒再次感染公司LAN
    [恢]hdu 2032
    [恢]hdu 2042
    [恢]hdu 2033
    [恢]hdu 2039
    [恢]hdu 2029
    [恢]hdu 2010
    [恢]hdu 2016
  • 原文地址:https://www.cnblogs.com/yxwkf/p/5119151.html
Copyright © 2011-2022 走看看