HDU 2852 KiKi's K-Number(离线+树状数组)

题目链接

省赛训练赛上一题，貌似不难啊。当初，没做出。离线+树状数组+二分。

 1 #include <cstdio>

 2 #include <cstring>

 3 #include <iostream>

 4 using namespace std;

 5 #define N 100000

 6 int p[100100];

 7 int qur[300001][3];

 8 int lowbit(int t)

 9 {

10     return t&(-t);

11 }

12 void insert(int t,int d)

13 {

14     while(t <= N)

15     {

16         p[t] += d;

17         t += lowbit(t);

18     }

19 }

20 int getsum(int t)

21 {

22     int sum = 0;

23     while(t)

24     {

25         sum += p[t];

26         t -= lowbit(t);

27     }

28     return sum;

29 }

30 int bin(int x)

31 {

32     int str,end,mid;

33     if(x > getsum(N))

34     return -1;

35     str = 1;

36     end = N;

37     while(str < end)

38     {

39         mid = (str + end)/2;

40         if(getsum(mid) < x)

41         str = mid + 1;

42         else

43         end = mid;

44     }

45     return str;

46 }

47 int main()

48 {

49     int n,i;

50     while(scanf("%d",&n)!=EOF)

51     {

52         memset(p,0,sizeof(p));

53         for(i = 0;i < n;i ++)

54         {

55            scanf("%d",&qur[i][0]);

56            if(qur[i][0] == 0||qur[i][0] == 1)

57            scanf("%d",&qur[i][1]);

58            else

59            scanf("%d%d",&qur[i][1],&qur[i][2]);

60         }

61         for(i = 0;i < n;i ++)

62         {

63             if(qur[i][0] == 0)

64             insert(qur[i][1],1);

65             else if(qur[i][0] == 1)

66             {

67                 if(getsum(qur[i][1])-getsum(qur[i][1]-1) > 0)

68                 insert(qur[i][1],-1);

69                 else

70                 printf("No Elment!\n");

71             }

72             else

73             {

74                 int flag;

75                 flag = bin(getsum(qur[i][1])+qur[i][2]);

76                 if(flag == -1)

77                 printf("Not Find!\n");

78                 else

79                 printf("%d\n",flag);

80             }

81         }

82     }

83     return 0;

84 }