HDU-1541 樹狀數組（基礎題）

來源資料關於y座標遞增，所以只需統計x座標小於給定座標的數目作為星等。

/* * hdu-1541 stars * mike-w * 2011-12-9 * ------------------- * tag: * 樹狀數組 */#include<iostream>#include<cstdio>#include<cstdlib>#include<cstring>using namespace std;const int maxn=15555;const int maxco=32222;int seq[maxco];int c[maxn];int n;inline int lowbit(int x){return x&(-x);}int add(int p,int inc){while(p<=maxco)seq[p]+=inc,p+=lowbit(p);return 0;}int sum(int p){int ret=0;while(p>0)ret+=seq[p],p-=lowbit(p);return ret;}int main(void){#ifndef ONLINE_JUDGEfreopen("in","r",stdin);#endifint i,x,y;while(scanf("%d",&n)!=EOF){memset(seq,0,sizeof(seq));memset(c,0,sizeof(c));for(i=0;i<n;i++){scanf("%d%d",&x,&y);c[sum(x+1)]++;add(x+1,1);}for(i=0;i<n;i++)printf("%d\n",c[i]);}return 0;}