Acdream1157---Segments （CDQ分治）

  1 #include <cstdio>
  2 #include <string>
  3 #include <vector>
  4 #include <cstdlib>
  5 #include <cstring>
  6 #include <iostream>
  7 #include <algorithm>
  8 using namespace std;
  9 const int maxn = 1e5+10;
 10 struct Node
 11 {
 12     int idx,l,r,delt;
 13     int kind;
 14     bool operator < (const Node &rhs)const
 15     {
 16         return l < rhs.l ;
 17     }
 18 }node[maxn];
 19 int ans[maxn],del[maxn];
 20 //-------------BIT---------       //此处树状数组反向写的，用于查询 大于等于x的数有多少个
 21 inline int lowbit (int x)
 22 {
 23     return x & -x;
 24 }
 25 int arr[maxn],MAX;
 26 void add (int x,int d)
 27 {
 28     while (x)
 29     {
 30         arr[x] += d;
 31         x -= lowbit(x);
 32     }
 33 }
 34 int sum(int x)
 35 {
 36     int ans = 0;
 37     while (x <= MAX)
 38     {
 39         ans += arr[x];
 40         x += lowbit(x);
 41     }
 42     return ans;
 43 }
 44 //--------------离散化-----
 45 int vec[maxn],vec_idx;
 46 int hash_(int x)
 47 {
 48     return lower_bound(vec,vec+vec_idx,x) - vec + 1;
 49 }
 50 //------------------------
 51 void CDQ(int l,int r)
 52 {
 53     if (l == r)
 54         return;
 55     int mid = (l + r) >> 1;
 56     CDQ(l,mid);
 57     CDQ(mid+1,r);
 58     int j = l;
 59     for (int i = mid+1; i <= r; i++)
 60     {
 61         if (node[i].kind == 2)
 62         {
 63             for ( ;j <= mid && node[j].l <= node[i].l; j++)
 64             {
 65                 if (node[j].kind == 1)
 66                 {
 67                     add(hash_(node[j].r),node[j].delt);
 68                 }
 69             }
 70             ans[node[i].idx] += sum(hash_(node[i].r));
 71         }
 72     }
 73     for (int i = l; i < j; i++)
 74         if ( node[i].kind == 1)
 75             add(hash_(node[i].r),-node[i].delt);
 76     inplace_merge(node+l,node+mid+1,node+r+1);
 77 }
 78 int vis[maxn];
 79 int main(void)
 80 {
 81     #ifndef ONLINE_JUDGE
 82         freopen("in.txt","r",stdin);
 83     #endif
 84     int n;
 85     while (~scanf ("%d",&n))
 86     {
 87         int cnt = 0;
 88         vec_idx = 0;
 89         memset(arr,0,sizeof(arr));
 90         memset(ans,0,sizeof(ans));
 91         memset(vis,0,sizeof(vis));
 92         vector<int>vv;
 93         for (int i = 1; i <= n; i++)
 94         {
 95             char op[3];
 96             scanf ("%s",op);
 97             if (op[0] == ‘D‘)
 98             {
 99                 scanf ("%d%d",&node[i].l,&node[i].r);
100                 node[i].kind = 1;
101                 node[i].idx = i;
102                 node[i].delt = 1;
103                 vec[vec_idx++] = node[i].r;
104                 vv.push_back(i);
105             }
106             if (op[0] == ‘Q‘)
107             {
108                 scanf ("%d%d",&node[i].l,&node[i].r);
109                 node[i].kind = 2;
110                 node[i].idx = i;
111                 vec[vec_idx++] = node[i].r;
112                 vis[i] = 1;
113             }
114             if (op[0] == ‘C‘)
115             {
116                 int tmp;
117                 scanf ("%d",&tmp);
118                 node[i].kind = 1;
119                 node[i].l = node[vv[tmp-1]].l;
120                 node[i].r = node[vv[tmp-1]].r;
121                 node[i].delt = -1;                    // 对于删除的边类型与增加的相同但是，操作的时候是-1
122                 node[i].idx = i;
123             }
124         }
125         sort(vec,vec+vec_idx);
126         vec_idx = unique(vec,vec+vec_idx) - vec;
127         MAX = vec_idx + 10;
128         CDQ(1,n);
129         for (int i = 1; i <= n; i++)
130         {
131             if (vis[i])
132                 printf("%d\n",ans[i]);
133         }
134     }
135     return 0;
136 }