Poj 2352 Star

 1 #include <iostream>
 2 #include <cstdio>
 3 using namespace std;
 4 #define Max 32010
 5 int star[Max];
 6 int level[Max];
 7 int Lowbit(int x);
 8 int Sum(int k);
 9 void Update(int k);
10 int main()
11 {
12     //freopen("D:\\acm.txt","r",stdin);
13     int xNum = 0, yNum = 0;
14     int lineNum = 0;
15     scanf("%d",&lineNum);
16     for (int i = 0; i < lineNum; ++i){
17         scanf("%d%d", &xNum, &yNum);
18         level[Sum(xNum + 1)]++;//xNum要加1或者一个正整数，避免为0，否则会报错
19         Update(xNum + 1);
20     }
21     for (int i = 0; i < lineNum; ++i)
22         printf("%d\n",level[i]);
23     return 0;
24 }
25 int Lowbit(int x){
26     return x & (-x);//返回最后一个1的位置开始的数
27 }
28 int Sum(int k){　　//前k项和
29     int judge = 0;
30     while (k){
31         judge = judge + star[k];
32         k = k - Lowbit(k);//
33     }
34     return judge;
35 }
36 void Update(int k){//修改第k项，更新之后的内容
37     while (k < Max){
38         star[k]++;
39         k = k + Lowbit(k);
40     }
41 }