hdu 1541 Stars
![](http://acm.hdu.edu.cn/data/images/1541-1.jpg)
For example, look at the map shown on the figure above. Level of the star number 5 is equal to 3 (it's formed by three stars with a numbers 1, 2 and 4). And the levels of the stars numbered by 2 and 4 are 1. At this map there are only one star of the level 0, two stars of the level 1, one star of the level 2, and one star of the level 3.
You are to write a program that will count the amounts of the stars of each level on a given map.
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define N 15003
#define M 32003
int c[M],hash[N];
int lb(int x) //基本的树状数组模板呀
{
return x&(-x);
}
void updata(int i)
{
for(;i<=M;i+=lb(i))
c[i]+=1;
}
int rs(int k)
{
int sum=0;
for(;k>0;k-=lb(k))
sum+=c[k];
return sum;
}
int main()
{ //freopen("in.txt","r",stdin);
int i,x,y,n;
while(scanf("%d",&n)!=EOF)
{
memset(c,0,sizeof(c));
memset(hash,0,sizeof(hash));
for(i=0;i<n;i++)
{
scanf("%d%d",&x,&y);
x++; //开始时这个忘记勒,出现了X=0;树状数组这个必须要注意!!!悲剧!
hash[rs(x)]++;
updata(x);
}
for(i=0;i<n;i++)
printf("%d\n",hash[i]);
}
return 0;
}
-----江财小子