hdu--2852--树状数组

  1 #include <iostream>
  2 #include <cstring>
  3 using namespace std;
  4 
  5 const int size = 100010;
  6 int tree[size];//  tree[x] 即 小于等于x的数有几个
  7 
  8 int lowbit( int x )
  9 {
 10     return x & -x;
 11 }
 12 
 13 void update( int x , int var )
 14 {
 15     while( x<size )
 16     {
 17         tree[x] += var;
 18         x += lowbit(x);
 19     }
 20 }
 21 
 22 int getNum( int x )
 23 {
 24     int cnt = 0;
 25     while( x )
 26     {
 27         cnt += tree[x];
 28         x -= lowbit(x);
 29     }
 30     return cnt;
 31 }
 32 
 33 int find( int x , int k )
 34 {
 35     int l = x+1 , r = size-5 , ans = size , mid;
 36     int temp = getNum(x);
 37     int val;
 38     while( l<r )
 39     {
 40         mid = l + (r-l)/2;
 41         val = getNum(mid) - temp;
 42         if( val<k )
 43         {
 44             l = mid+1;
 45         }
 46         else
 47         {
 48             r = mid;
 49             if( ans > mid )
 50                 ans = mid;
 51         }
 52     }
 53     return ans;
 54 }
 55 
 56 int main()
 57 {
 58     cin.sync_with_stdio(false);
 59     int n , num , m ,ans , k;
 60     while( cin >> n )
 61     {
 62         memset( tree , 0 , sizeof(tree) );
 63         while( n-- )
 64         {
 65             //scanf("%d",&m);
 66             cin >> m;
 67             if( !m )
 68             {
 69                 //scanf("%d",&num);
 70                 cin >> num;
 71                 update( num , 1 );
 72             }
 73             else if( m==1 )
 74             {
 75                 //scanf("%d",&num);
 76                 cin >> num;
 77                 if( getNum(num) - getNum(num-1) == 0 )
 78                 {
 79                     //printf("No Elment!\n");
 80                     cout << "No Elment!" << endl;
 81                 }
 82                 else
 83                 {
 84                     update( num , -1 );
 85                 }
 86             }
 87             else
 88             {
 89                 //scanf("%d %d",&num,&k);
 90                 cin >> num >> k;
 91                 ans = find( num , k );
 92                 if( ans == size )
 93                     //printf("Not Find!\n");
 94                     cout << "Not Find!" << endl;
 95                 else
 96                     //printf("%d\n",ans);
 97                     cout << ans << endl; 
 98             }
 99         }
100     }
101     return 0;
102 }

 1 #include <iostream>
 2 #include <cstring>
 3 using namespace std;
 4 
 5 const int size = 100010;
 6 int hash[size];
 7 
 8 int main()
 9 {
10     cin.sync_with_stdio(false);
11     int m , k , num , maxNum , cnt , choice;
12     bool flag;
13     while( cin >> m )
14     {
15         maxNum = 0;
16         memset( hash , 0 , sizeof(hash) );
17         while( m-- )
18         {
19             cin >> choice;
20             if( !choice )
21             {
22                 cin >> num;
23                 hash[num] ++;
24                 if( maxNum < num )
25                     maxNum = num;
26             }
27             else if( choice == 1 )
28             {
29                 cin >> num;
30                 if( hash[num] )
31                 {
32                     hash[num] --;
33                 }
34                 else
35                 {
36                     cout << "No Elment!" << endl;
37                 }
38             }
39             else
40             {
41                 flag = false;
42                 cnt = 0;
43                 cin >> num >> k;
44                 for( int i = num+1 ; i<=maxNum ; i++ )
45                 {
46                     if( hash[i] )
47                     {
48                         cnt += hash[i];
49                         if( cnt>=k )
50                         {
51                             cout << i << endl;
52                             flag = true;
53                             break;
54                         }
55                     }
56                 }
57                 if( !flag )
58                     cout << "Not Find!" << endl;
59             }
60         }
61     }
62     return 0;
63 }