bzoj3192 [JLOI2013]删除物品

　　用数组表示两个栈，将两个栈的栈顶并在一起，用树状数组维护一下操作即可。

　　代码

 1 #include<cstdio>
 2 #include<algorithm>
 3 #include<map>
 4 #define lb(x) (x&-x)
 5 using namespace std;
 6 const int N = 501010;
 7 int n,m,i,id[N],a[N],b[N],c[N],top,tot;
 8 long long ans;
 9 map<int,int> ma;
10 void cc(int x,int w)
11 {
12     while (x<=n+m)
13     {
14         c[x]+=w;
15         x+=lb(x);
16     }
17 }
18 int sum(int x)
19 {
20     int ans=0;
21     while (x)
22     {
23         ans+=c[x];
24         x-=lb(x);
25     }
26     return ans;
27 }
28 int main()
29 {
30     scanf("%d%d",&n,&m);
31     for (i=1;i<=n;i++)
32     scanf("%d",&a[i]),b[i]=a[i];
33     for (i=n+1;i<=n+m;i++)
34     scanf("%d",&a[i]),b[i]=a[i];
35     sort(b+1,b+1+m+n);
36     for (i=1;i<=n+m;i++) 
37     if (ma[b[i]]==0) ma[b[i]]=++tot;
38     for (i=1;i<=n+m;i++) a[i]=ma[a[i]];
39     for (i=1;i<=n;i++)
40         id[a[i]]=n-i+1;
41     for (i=1;i<=m;i++)
42         id[a[n+i]]=n+i;
43     
44     for (i=1;i<=n+m;i++) cc(i,1);
45     
46     top=n;
47     for (i=n+m;i>=1;i--)
48     {
49         if (id[i]<=top)
50         {
51         ans+=sum(top)-sum(id[i]);
52         top=id[i];
53         }
54         else
55         {
56         ans+=sum(id[i]-1)-sum(top);
57         top=id[i];
58         }
59         cc(id[i],-1);
60     }
61     printf("%lld\n",ans);
62 }

posted @ 2016-05-09 13:08 fzmh 阅读(139) 评论(0) 收藏举报

刷新页面返回顶部