poj2352

每次只需计算小于等于当前x值得个数有多少即可。

ac代码：

treap

#include<bits/stdc++.h>
using namespace std;
#define per(i,a,b) for(int i=a;i <= b;i++)
#define Max(a,b) a=max(a,b)
#define Min(a,b) a=min(a,b)
#define Sz(x) (int)x.size()
typedef long long ll;
ll gcd(ll a,ll b){while(b){ll t=b;b=a%b;a=t;} return a;}
const int inf=0x3f3f3f3f;
#define siz 15005
int n,x,y,ans[siz];
struct TreapNode
{
    int rnd,sz;
    TreapNode* child[2];
    int x;
    TreapNode(int X):x(X){
        rnd=rand();
        sz=1;
        child[0]=child[1]=NULL;
    }
    void update(){sz=1;if(child[0]!=NULL)sz+=child[0]->sz; if(child[1]!=NULL)sz+=child[1]->sz;}
}*root,*tmp;
void Rotate(TreapNode*&u,int type)
{
    tmp=u->child[type^1];
    u->child[type^1]=tmp->child[type];
    tmp->child[type]=u;
    u->update();tmp->update();
    u=tmp;
}
void Insert(TreapNode*&u,int xx)
{
    if(u==NULL){u=new TreapNode(xx);}
    else{
        int type=xx > u->x;
        Insert(u->child[type],xx);
        if(u->child[type]->rnd > u->rnd)Rotate(u,type^1);
    }
    u->update();//子节点新插入，所以要更新！
}
int FindNum(TreapNode*u,int key)//小于key的数量
{
    int ret=0;
    if(u == NULL)return 0;
    if(u->x <= key){
        ret=1;
        if(u->child[0]!=NULL)ret+=u->child[0]->sz;
        return ret+FindNum(u->child[1],key);
    }
    else if(u->x > key)return FindNum(u->child[0],key);
}

int main()
{
    std::ios::sync_with_stdio(false);
    while(scanf("%d",&n)!=EOF){
        memset(ans,0,sizeof(ans));
        root=NULL;
        for(int i=1;i<=n;i++){
            scanf("%d %d",&x,&y);
            ans[FindNum(root,x)]++;
            Insert(root,x);
        }
        per(i,0,n-1)printf("%d\n",ans[i]);
    }

    return 0;
}

 

树状数组

#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
using namespace std;
#include<stdio.h>
#include <cstdlib>
#include<malloc.h>
#include<algorithm>
#include<cmath>
#include<map>
#include<string.h>
#include<string>
#include<vector>
#include<stack>
#include<set>
#include<queue>
#include<list>
#include<time.h>
int Max(int a, int b) { return a > b ? a : b; }
int Min(int a, int b) { return a > b ? b : a; }
#define FOR(i,a,b) for(int i=a;i<=b;i++)
const int MAX = 0x3f3f3f3f;
typedef long long LL;
typedef unsigned long long ull;
#define max 15005
#define maxn 32005
int c[maxn];
int ans[maxn];
int n;
int lowbit(int k)
{
    return k&-k;
}
void add(int x,int v)
{
    for (int i = x; i <= maxn; i += lowbit(i)) {
        c[i] += v;
    }
}
int query(int x)
{
    int ans = 0;
    for (int i = x; i > 0; i -= lowbit(i)) {
        ans += c[i];
    }
    return ans;
}
int main()
{
    //freopen("e://outtest.txt", "w", stdout);
    //freopen("e://test.txt", "r", stdin);
    while (scanf("%d", &n) != EOF&&n!=0) {
        memset(c, 0, sizeof(c));
        memset(ans, 0, sizeof(ans));
        int x, y;
        FOR(i, 1, n) {
            scanf("%d %d", &x, &y);
            ++x;
            ans[query(x)]++;
            add(x, 1);
        }
        FOR(j, 0, n - 1)printf("%d\n", ans[j]);
    }
    return 0;
}