【树状数组】 ACdream 1127 Base Station

压根没有想到用树状数组可以做。。。。一开始用KD树做，结果超时了。。。KD树查询的时候太慢了。。而且对于这道题目，貌似可以人工构造出一组数据把KD树卡成一条链。。。。。跪掉了。。

用树状数组就离线查询呗。。。把查询和点都按一维从小到大排好序，然后按另一维单点插入就好嘞。。。

#include <iostream>#include <sstream>#include <algorithm>#include <vector>#include <queue>#include <stack>#include <map>#include <set>#include <bitset>#include <cstdio>#include <cstring>#include <cstdlib>#include <cmath>#include <climits>#define maxn 200005#define eps 1e-6#define mod 10007#define INF 99999999#define lowbit(x) (x&(-x))#define lson o<<1, L, mid#define rson o<<1 | 1, mid+1, Rtypedef long long LL;using namespace std;LL xx1, yy1, xx2, yy2;struct point{LL x, y;}po[maxn];struct query{LL r1, r2;int res;int number;}q[maxn];int tree[maxn];LL yy[maxn];int ycnt, n, m;int cmp1(LL a, LL b){return a<b;}int cmp2(point a, point b){return a.x>b.x;}int cmp3(query a, query b){if(a.r1 == b.r1) return a.r2<b.r2;return a.r1>b.r1;}int cmp4(query a, query b){return a.number<b.number;}void init(void){memset(tree, 0, sizeof tree);}void add(int x){for(int i = x; i > 0; i-=lowbit(i)) tree[i]++;}int sum(int x){int ans = 0;for(int i = x; i <= ycnt; i+=lowbit(i)) ans += tree[i];return ans;}void read(void){int i;LL tmpx, tmpy;ycnt = 0;scanf("%d", &n);for(i = 1; i <= n; i++) {scanf("%lld%lld", &tmpx, &tmpy);po[i].x = (tmpx-xx1)*(tmpx-xx1) + (tmpy-yy1)*(tmpy-yy1);po[i].y = (tmpx-xx2)*(tmpx-xx2) + (tmpy-yy2)*(tmpy-yy2);yy[ycnt++] = po[i].y;}scanf("%d", &m);for(i = 1; i <= m; i++) {scanf("%lld%lld", &q[i].r1, &q[i].r2);q[i].number = i;q[i].r1*=q[i].r1;q[i].r2*=q[i].r2;yy[ycnt++] = q[i].r2;}}void work(void){int i, j;sort(yy+1, yy+ycnt+1, cmp1);for(i = 2, j = 2; i <= ycnt; i++)if(yy[i] != yy[i-1])yy[j++] = yy[i];ycnt = j-1;sort(po+1, po+n+1, cmp2);sort(q+1, q+m+1, cmp3);}int search(LL tmp){int bot = 1, top = ycnt, mid;while(top>=bot) {mid = (top+bot)>>1;if(yy[mid] == tmp) break;if(yy[mid] > tmp) top = mid-1;else bot = mid+1;}return mid;}void debug(void){int i;printf("BBBB\n");for(i = 1; i <= ycnt; i++)printf("%d\n", search(yy[i]));}void solve(void){int i, j;for(i = 1, j = 1; i <= m; i++) {while(j <= n && po[j].x >= q[i].r1) add(search(po[j++].y));q[i].res = sum(search(q[i].r2));}sort(q+1, q+m+1, cmp4);for(i = 1; i <= m; i++)printf("%d\n", q[i].res);}int main(void){while(scanf("%lld%lld%lld%lld", &xx1, &yy1, &xx2, &yy2)!=EOF) {init();read();work();solve();}return 0;}