POJ2352 Stars（树状数组 or SplayTree）

版权声明：希望有人转(^_^) https://blog.csdn.net/Sunshine_cfbsl/article/details/52197762

发现网上并没有这一题的Splay做法。。。SplayTree模板点这里
其实是水题，所以不做讲解。
这里只是来贡献代码。。。

树状数组：

/*
ID: Sunshine_cfbsl
LANG: C++
*/
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<iostream>
using namespace std;

int C[32010], n, ans[15010];

int lowbit(int x) {
    return x & (-x);
}

int sum(int x) {
    int ret = 0;
    while(x > 0) {
        ret += C[x];
        x -= lowbit(x);
    }
    return ret;
}

void add(int x) {
    while(x <= 32001) {
        C[x]++;
        x += lowbit(x);
    }
}

int main() {
    int i, tmp;
    scanf("%d", &n);
    for(i = 1; i <= n; i++) {
        scanf("%d", &tmp);
        ans[sum(++tmp)]++;
        add(tmp);
        scanf("%d", &tmp);
    }
    for(i = 0; i < n; i++) printf("%d\n", ans[i]);
    return 0;
}

SplayTree：

/*
ID: Sunshine_cfbsl
LANG: C++
*/
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;

const int MAXN = 150010;
struct Splay_Tree {
    int fa[MAXN], ch[MAXN][2], data[MAXN], size[MAXN], v[MAXN], r, pn;
    void clear(int x) {
        r = pn = 1;
        memset(fa, 0, sizeof(fa));
        memset(ch, 0, sizeof(ch));
        memset(data, 0, sizeof(data));
        memset(v, 0, sizeof(v));
        memset(size, 0, sizeof(size));
        size[1] = v[1] = 1;
        data[1] = x;
    }
    void maintain(int p) {
        size[p] = size[ch[p][0]]+size[ch[p][1]]+v[p];
    }
    void Rotate(int p, bool t) {
        int f = fa[p];
        fa[ch[f][t^1] = ch[p][t]] = f;
        fa[ch[fa[f]][ch[fa[f]][1]==f] = p] = fa[f];
        ch[fa[f] = p][t] = f;
        maintain(f);
    }
    void splay(int x) {
        int p;
        while(fa[x]) {
            p = fa[x];
            if(!fa[p]) {
                Rotate(x, x==ch[p][0]);
                break;
            }
            bool f = x==ch[p][0], f1 = p==ch[fa[p]][0], f2 = p==ch[fa[p]][1];
            Rotate(f?f1?p:x:f2?p:x, f);
            Rotate(x, f1);
        }
        maintain(x);
        r = x;
    }
    void insert(int x) {
        int p = r;
        while(true) {
            size[p]++;
            if(x == data[p]) {
                v[p]++;
                break;
            }
            if((x<data[p] && !ch[p][0]) || (x>data[p] && !ch[p][1])) {
                fa[++pn] = p;
                ch[p][x>data[p]] = pn;
                data[pn] = x;
                size[pn] = v[pn] = 1;
                p = pn;
                break;
            }
            p = ch[p][x>data[p]];
        }
        splay(p);
    }
}tree;

int main() {
    int i, n, tmp, cnt[MAXN];
    scanf("%d", &n);
    scanf("%d", &tmp);
    tree.clear(tmp);
    cnt[0]++;
    scanf("%d", &tmp);
    for(i = 2; i <= n; i++) {
        scanf("%d", &tmp);
        tree.insert(tmp);
        if(tree.ch[tree.r][0]) cnt[tree.size[tree.ch[tree.r][0]]+tree.v[tree.r]-1]++;
        else cnt[tree.v[tree.r]-1]++;
        scanf("%d", &tmp);
    }
    for(i = 0; i < n; i++) printf("%d\n", cnt[i]);
    return 0;
}