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  • Codeforces 446-C DZY Loves Fibonacci Numbers 同余 线段树 斐波那契数列

    C. DZY Loves Fibonacci Numbers
    time limit per test
    4 seconds
    memory limit per test
    256 megabytes
    input
    standard input
    output
    standard output

    In mathematical terms, the sequence Fn of Fibonacci numbers is defined by the recurrence relation

    F1 = 1; F2 = 1; Fn = Fn - 1 + Fn - 2 (n > 2).

    DZY loves Fibonacci numbers very much. Today DZY gives you an array consisting of n integers: a1, a2, ..., an. Moreover, there are m queries, each query has one of the two types:

    1. Format of the query "1 l r". In reply to the query, you need to add Fi - l + 1 to each element ai, where l ≤ i ≤ r.
    2. Format of the query "2 l r". In reply to the query you should output the value of modulo 1000000009 (109 + 9).

    Help DZY reply to all the queries.

    Input

    The first line of the input contains two integers n and m (1 ≤ n, m ≤ 300000). The second line contains n integers a1, a2, ..., an (1 ≤ ai ≤ 109) — initial array a.

    Then, m lines follow. A single line describes a single query in the format given in the statement. It is guaranteed that for each query inequality 1 ≤ l ≤ r ≤ n holds.

    Output

    For each query of the second type, print the value of the sum on a single line.

    Sample test(s)
    Input
    4 4
    1 2 3 4
    1 1 4
    2 1 4
    1 2 4
    2 1 3
    Output
    17
    12
    Note

    After the first query, a = [2, 3, 5, 7].

    For the second query, sum = 2 + 3 + 5 + 7 = 17.

    After the third query, a = [2, 4, 6, 9].

    For the fourth query, sum = 2 + 4 + 6 = 12.

    官方题解:

    As we know,

    Fortunately, we find that

    So,

    With multiplicative inverse, we find,

    Now,

    As you see, we can just maintain the sum of a Geometric progression

    This is a simple problem which can be solved with segment tree in .

    这道题是Fibonacci数列通项公式的应用,比较经典。至少我是不可能想到斐波那契数列与等比数列有任何关联。还有一点,在程序内层循环中,快速幂的时间复杂度是不容忽视的(估计是线段树写抽了),这里既然公比恒定,可先与处理一下。

    #include<iostream>
    #include<cstdio>
    #include<algorithm>
    #include<cstring>
    #include<cmath>
    using namespace std;
    #define MAXN 310000
    #define MAXT 1210000
    #define MOD 1000000009
    #define lch (now<<1)
    #define rch (now<<1^1)
    void nextInt(int &x)
    {
            char ch;
            x=0;
            while (ch=getchar(),ch>'9'||ch<'0');
            do
                    x=x*10+ch-'0';
            while (ch=getchar(),ch<='9'&&ch>='0');
    }
    int n,m;
    typedef long long qword;
    int num[MAXN];
    qword val1,val2,val3,val4,val3_n,val4_n,mod;
    qword val3_pow[MAXN],val4_pow[MAXN];
    qword pow_mod(qword x,qword y,int mod)
    {
            qword ret=1;
            while (y)
            {
                    if (y&1)ret=ret*x%mod;
                    x=x*x%mod;
                    y>>=1;
            }
            return ret;
    }
    struct node
    {
            int l,r;
            qword sum;
            qword inc3,inc4;
    }tree[MAXT];
    inline void update_sum_3(int now,int inc3)
    {
            qword temp;
            temp=inc3*(val3_pow[tree[now].r-tree[now].l+1]-1)%MOD*val3_n%MOD;
        //    temp=(temp+MOD)%MOD;
            tree[now].sum=(tree[now].sum+temp)%MOD;
    }
    inline void update_sum_4(int now,int inc4)
    {
            qword temp;
            temp=inc4*(val4_pow[tree[now].r-tree[now].l+1]-1)%MOD*val4_n%MOD;
            temp=(-temp+MOD)%MOD;
            tree[now].sum=(tree[now].sum+temp)%MOD;
    }
    inline void down(int now)
    {
            if (tree[now].l==tree[now].r)
            {
                    if (tree[now].inc3)
                    {
                            tree[now].inc3=0;
                    }
                    if (tree[now].inc4)
                    {
                            tree[now].inc4=0;
                    }
                    return ;
            }
            if (tree[now].inc3)
            {
                    qword temp;
                    tree[lch].inc3=(tree[lch].inc3+tree[now].inc3)%MOD;
            //        tree[lch].inc3%=MOD;
                    update_sum_3(lch,tree[now].inc3);
                    tree[rch].inc3+=temp=val3_pow[tree[lch].r-tree[lch].l+1]*tree[now].inc3%MOD;
                    tree[rch].inc3%=MOD;
                    update_sum_3(rch,temp);
                    tree[now].inc3=0;
            }
            if (tree[now].inc4)
            {
                    qword temp;
                    tree[lch].inc4+=tree[now].inc4;
                    tree[lch].inc4%=MOD;
                    update_sum_4(lch,tree[now].inc4);
                    tree[rch].inc4+=temp=val4_pow[tree[lch].r-tree[lch].l+1]*tree[now].inc4%MOD;
                    tree[rch].inc4%=MOD;
                    update_sum_4(rch,temp);
                    tree[now].inc4=0;
            }
    }
    inline void update(int now)
    {
            if (tree[now].l!=tree[now].r)
                    tree[now].sum=(tree[lch].sum+tree[rch].sum)%MOD;
    }
    void init()
    {
            /*//{{{
            int i;
               for (i=1;i<MOD;i++)
               {
               if ((qword)i*i%MOD==5)
               {
               val1=i;
               break;
               }
               }
               cout<<val1<<endl;
               for (i=1;i<MOD;i++)
               {
               if ((qword)i*5%MOD==val1)
               {
               val2=i;
               break;
               }
               }
               cout<<val2<<endl;
               for (i=1;i<MOD;i++)
               {
               if ((qword)i*2%MOD-1==val1)
               {
               val3=i;
               break;
               }
               }
               cout<<val3<<endl;
               for (i=1;i<MOD;i++)
               {
               if ((qword)i*2-1==(-val1+MOD)%MOD)
               {
               val4=i;
               break;
               }
               }
               cout<<val4<<endl;//}}}*/
            val1=383008016;//sqrt(5)
            val2=276601605;//sqrt(5)/5
            val3=691504013;//(1+sqrt(5))/2
            val4=308495997;//(1-sqrt(5))/2
            int i;
            qword temp=val3;
            val3_pow[0]=1;
            for (i=1;i<MAXN;i++)
            {
                    val3_pow[i]=val3_pow[i-1]*val3%MOD;;
            }
            val4_pow[0]=1;
            for (i=1;i<MAXN;i++)
            {
                    val4_pow[i]=val4_pow[i-1]*val4%MOD;
            }
            val3_n=pow_mod(val3-1,MOD-2,MOD);
            val4_n=pow_mod(val4-1,MOD-2,MOD);
            //fib(n)=val2*(val3^n-val4^n);
    }
    void build_tree(int now,int l,int r)
    {
            tree[now].l=l;
            tree[now].r=r;
            if (l==r)
            {
                    tree[now].sum=num[l];
                    return ;
            }
            int mid=(l+r)/2;
            build_tree(lch,l,mid);
            build_tree(rch,mid+1,r);
            update(now);
    }
    void add_val(int now,int l,int r,int rk)
    {
            if (tree[now].l==l&&tree[now].r==r)
            {
                    qword temp;
                    temp=val2*val3%MOD*val3_pow[rk]%MOD;
                    tree[now].inc3=(tree[now].inc3+temp)%MOD;
                    update_sum_3(now,temp);
                    temp=val2*val4%MOD*val4_pow[rk]%MOD;
                    tree[now].inc4=(tree[now].inc4+temp)%MOD;
                    update_sum_4(now,temp);
                    return ;
            }
            down(now);
            int mid=(tree[now].l+tree[now].r)>>1;
            if (r<=mid)
            {
                    add_val(lch,l,r,rk);
                    update(now);
                    return ;
            }
            if (mid<l)
            {
                    add_val(rch,l,r,rk);
                    update(now);
                    return ;
            }
            add_val(lch,l,mid,rk);
            add_val(rch,mid+1,r,rk-l+mid+1);
            update(now);
    }
    //ok
    qword query(int now,int l,int r)
    {
            if (tree[now].l==l&&tree[now].r==r)
            {
                    return tree[now].sum;
            }
            down(now);
            int mid=(tree[now].l+tree[now].r)>>1;
            if (r<=mid)
                    return query(lch,l,r);
            if (mid<l)
                    return query(rch,l,r);
            return (query(lch,l,mid)+query(rch,mid+1,r))%MOD;
    }
    
    int main()
    {
            freopen("input.txt","r",stdin);
            freopen("output.txt","w",stdout);
            //scanf("%d%d",&n,&m);
            nextInt(n);
            nextInt(m);
            int i,j,k,x,y,z;
            init();
            for (i=1;i<=n;i++)
                    nextInt(num[i]);
            build_tree(1,1,n);
            while (m--)
            {
                    nextInt(x);
                    nextInt(y);
                    nextInt(z);
                    if (x==1)
                    {
                            add_val(1,y,z,0);
                    }else
                    {
                            printf("%I64d
    ",query(1,y,z));
                    }
            }
    }
    by mhy12345(http://www.cnblogs.com/mhy12345/) 未经允许请勿转载

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  • 原文地址:https://www.cnblogs.com/mhy12345/p/3849794.html
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