HDU 2852 KiKi's K-Number【 树状数组 二分 】

 1 #include<iostream>  
 2 #include<cstdio>  
 3 #include<cstring> 
 4 #include <cmath> 
 5 #include<stack>
 6 #include<vector>
 7 #include<map> 
 8 #include<set>
 9 #include<queue> 
10 #include<algorithm>  
11 using namespace std;
12 
13 typedef long long LL;
14 const int INF = (1<<30)-1;
15 const int mod=1000000007;
16 const int maxn=100005;
17 
18 int a[maxn],c[maxn];
19 int k;
20 
21 int lowbit(int x){ return x &(-x);}
22 
23 int sum(int x){
24     int ret=0;
25     while(x>0){
26         ret+=c[x];x-=lowbit(x);
27     }
28     return ret;
29 }
30 
31 void add(int x,int d){
32     while(x<maxn){
33         c[x]+=d;x+=lowbit(x);
34     }
35 }
36 
37 int solve(int x){
38     int v=x;
39     int s=sum(x);
40     int kk=k+s;
41     int lb=1,ub=maxn,mid;
42     
43     for(int i=1;i<=100;i++){
44         mid=(lb+ub)/2;
45         if(sum(mid) < kk) lb =mid;
46         else ub = mid;
47     //    printf("lb = %d  ub = %d  mid = %d\n",lb,ub,mid);
48     }
49     return ub;
50 }
51 
52 
53 int main(){
54     int m;
55     while(scanf("%d",&m) != EOF){
56         memset(c,0,sizeof(c));
57         while(m--){
58             int cmd;
59             scanf("%d",&cmd);
60             if(cmd == 0){
61                 int x;
62                 scanf("%d",&x);
63                 add(x,1);
64             }
65             if(cmd == 1){
66                 int x;
67                 scanf("%d",&x);
68                 if(sum(x) - sum(x-1) == 0) printf("No Elment!\n");
69                 else add(x,-1);
70             }
71             if(cmd == 2){
72                 int x;
73                 scanf("%d %d",&x,&k);
74                 if(sum(maxn-1) - sum(x) < k) printf("Not Find!\n");
75                 else  printf("%d\n",solve(x));
76             }
77         }
78     }
79     return 0;
80 }