LOJ P10114 数星星 stars 题解

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<algorithm>
 5 #define maxn 15000+10
 6 #define maxm 32000+10+1
 7 using namespace std;
 8 inline int read() 
 9 {
10     int x=0;
11     bool f=1;
12     char c=getchar();
13     for(; !isdigit(c); c=getchar()) if(c=='-') f=0;
14     for(; isdigit(c); c=getchar()) x=(x<<3)+(x<<1)+c-'0';
15     if(f) return x;
16     return 0-x;
17 }
18 inline void write(int x)
19 {
20     if(x<0){putchar('-');x=-x;}
21     if(x>9)write(x/10);
22     putchar(x%10+'0');
23 }
24 int n;
25 int tree[maxm],ans[maxn];
26 inline int lowbit(int num)
27 {
28     return num&(-num);
29 }
30 inline void build(int s,int num)
31 {
32     for(int i=s;i<=maxm;i+=lowbit(i)) tree[i]+=num; 
33 }
34 inline int ask(int s)
35 {
36     int ans=0;
37     for(int i=s;i>=1;i-=lowbit(i)) ans+=tree[i];
38     return ans;
39 }
40 int main()
41 {
42     n=read();
43     for(int i=1;i<=n;i++)
44     {
45         int x,y;
46         x=read();y=read();
47         x++;
48         int res=ask(x);
49         ans[res]++; 
50         build(x,1);
51     }
52     for(int i=0;i<=n-1;i++) 
53     {
54         write(ans[i]);
55         printf("\n");
56     }
57     return 0;
58 }