幻想月面战争

发表于

这是题解呢

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
#include<cstdio>
#define umax 100005

int n,m;
double opi[umax];

struct node{
    int l,r;
    node* ls,* rs;
    double v,mul;

    node(int l,int r,node* ls,node* rs):
        l(l),r(r),ls(ls),rs(rs),v(ls->v*rs->v),mul(1) {}
    node(int l,int r,node* ls,node* rs,double v):
        l(l),r(r),ls(ls),rs(rs),v(v),mul(1) {}
    void covermul(double k)
    {
        for(int i=l;i<=r;i++)
            v=v*k;
        mul=mul*k;
    }
    void pushup()
    {
        v=ls->v*rs->v;
    }
    void pushdown()
    {
        ls->covermul(mul);
        rs->covermul(mul);
        mul=1;
    }
    void update1(int l,int r,double k)
    {
        if(l > this->r||r < this->l) return;
        if(l <= this->l&&r >= this->r)
            covermul(k);
        else
        {
            pushdown();
            ls->update1(l,r,k);
            rs->update1(l,r,k);
            pushup();
        }
        return;
    }
    double query(int l,int r)
    {
        if(l > this->r||r < this->l) return 1.0;
        if(l <= this->l&&r >= this->r)
            return v;
        pushdown();
        return ls->query(l,r)*rs->query(l,r);
    }
    static node *build(int l,int r)
    {
        if(l>r) return NULL;
        else if(l==r)
        {
            return new node(l,r,NULL,NULL,opi[l]);
        }
        else
        {
            int mid=(l+r)>>1;
            return new node(l,r,build(l,mid),build(mid+1,r));
        }
    }
}*root;

int main()
{
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)   scanf("%lf",&opi[i]);
    for(int i=1;i<=n;i++)   opi[i]=1.0-opi[i];
    root=node::build(1,n);
    int tmp,l,r;
    double k;
    while(m--)
    {
        scanf("%d",&tmp);
        if(tmp==1)
        {
            scanf("%d%d%lf",&l,&r,&k);
            root->update1(l,r,k);
        }
        else if(tmp==0)
        {
            scanf("%d%d",&l,&r);
            printf("%.6lf\n",root->query(l,r));
        }
    }
    return 0;
}