UVA 11990``Dynamic'' Inversion(树套树)

树状数组套treap

#include <bits/stdc++.h>#include <iostream>#include <cstdio>#include <cmath>#include <cstring>#include <algorithm>using namespace std;#define LL long long #define pii pair<int, int>#define MP make_pair#define ls i << 1#define rs ls | 1#define md (ll + rr >> 1)#define lson ll, md, ls#define rson md + 1, rr, rs#define inf 0x3f3f3f3f#define mod 1000000007#define N 300010#define M 400020int readint() {    char c;    while((c = getchar()) && !(c >= '0' && c <= '9') && c != '-');    int ret = c - '0', sgn = 0;    if(c == '-') sgn = 1, ret = 0;    while((c = getchar()) && c >= '0' && c <= '9')        ret = ret * 10 + c - '0';    if(sgn) ret = -ret;    return ret;}int ch[N*25][2];  int rand_val[N*25], key[N*25], sz[N*25];  int tot, rt[N], a[N], n, m, s[N], id[N];int creat(int val) {      ++tot;      ch[tot][0] = ch[tot][1] = 0;      rand_val[tot] = rand();      key[tot] = val;      sz[tot] = 1;      return tot;  }int cmp(int x, int val) {      if(key[x] == val) return -1;      return val < key[x]? 0: 1;  }void push_up(int x) {      sz[x] = sz[ch[x][0]] + sz[ch[x][1]] + 1;  }  void rot(int &x, int d) {      int k = ch[x][!d];      ch[x][!d] = ch[k][d];      ch[k][d] = x;      push_up(x);      push_up(k);      x = k;  }  void insert(int &x, int val) {      if(x == 0) {          x = creat(val);          return;      }      int d = cmp(x, val);      if(d == -1)        d = 1;    insert(ch[x][d], val);      if(rand_val[ch[x][d]] > rand_val[x]) rot(x, d ^ 1);      push_up(x);  }  void del(int &x, int val) {      if(x == 0) return;      int d = cmp(x, val);      if(d == -1) {          if(!ch[x][0]) x = ch[x][1];          else if(!ch[x][1]) x = ch[x][0];          else {              int d2 = rand_val[ch[x][0]] > rand_val[ch[x][1]]? 1: 0;              rot(x, d2);              del(ch[x][d2], val);          }      }      else del(ch[x][d], val);      if(x) push_up(x);  } int kth_mi(int x, int val){    if(!x) return 0;    int d = cmp(x, val);    if(d <= 0)        return kth_mi(ch[x][0], val);    return sz[ch[x][0]] + 1 + kth_mi(ch[x][1], val);}int kth_mx(int x, int val){    if(!x) return 0;    int d = cmp(x, val);    if(d == -1 || d == 1)        return kth_mx(ch[x][1], val);    return sz[ch[x][1]] + 1 + kth_mx(ch[x][0], val);}void add(int x, int v){    for(; x <= n; x += x & -x) s[x] += v;}int query(int x){    int ret = 0;    for(; x > 0; x -= x & -x) ret += s[x];    return ret;}void build(){    for(int i = 1; i <= n; ++i)        for(int j = i; j <= n; j += j & -j)            insert(rt[j], a[i]);}void update(int x, int val){    for(; x <= n; x += x & -x) del(rt[x], val);}int sum_mi(int x, int val){    int ret = 0;    for(; x > 0; x -= x & -x) ret += kth_mi(rt[x], val);    return ret;}int sum_mx(int x, int val){    int ret = 0;    for(; x > 0; x -= x & -x) ret += kth_mx(rt[x], val);    return ret;}int main(){    while(scanf("%d%d", &n, &m) != EOF){        tot = 0;        for(int i = 1; i <= n; ++i){            scanf("%d", &a[i]);            rt[i] = s[i] = 0;            id[a[i]] = i;        }        LL ans = 0;        for(int i = n; i > 0; --i){            ans += query(a[i]);            add(a[i], 1);        }        build();        while(m--){            printf("%lld\n", ans);            int v;            scanf("%d", &v);            int L = sum_mx(id[v], v);            int R = sum_mi(n, v) - sum_mi(id[v]-1, v);            update(id[v], v);            ans -= (L + R);        }    }    return 0;}