bzoj2658: [Zjoi2012]小蓝的好友(mrx)

太神辣 treap的随机键值竟然能派上用场。。

要用不旋转的treap来进行维护区间信息

 #include<cstdio>
 #include<cstring>
 #include<cstdlib>
 #include<algorithm>
 #include<iostream>

 using namespace std;

 template<typename Q> Q &read(Q &x) {
     static char c, f;
     for(f = ; c = getchar(), !isdigit(c); ) if(c == '-') f = ;
     for(x = ; isdigit(c); c = getchar()) x = x *  + c - '';
     if(f) x = -x; return x;
 }
 template<typename Q> Q read() {
     static Q x; read(x); return x;
 }

 typedef long long LL;
 const int N =  + ;

 LL S(LL x) {
     return x * (x + ) >> ;
 }

 struct Node *null, *pis;
 struct Node {
     int sz, h, tag;
     LL ans;
     Node *ch[];

     Node() {}
     Node(int h) : h(h) {
         sz = , ans = tag = ;
         ch[] = ch[] = null;
     }

     void add(int d) {
         if(this == null) return;
         h += d, tag += d;
     }

     void maintain() {
         sz = ch[]->sz + ch[]->sz + ;
         ans = ;
         for(int c = ; c < ; c++) {
             ans += ch[c]->ans + S(ch[c]->sz) * (ch[c]->h - h);
         }
     }

     void down() {
         ch[]->add(tag);
         ch[]->add(tag);
         tag = ;
     }

     void *operator new(size_t) {
         return pis++;
     }
 }pool[N];

 Node *merge(Node *l, Node *r) {
     if(l == null) return r;
     if(r == null) return l;
     if(l->h < r->h) {
         l->down();
         l->ch[] = merge(l->ch[], r);
         return l->maintain(), l;
     }else {
         r->down();
         r->ch[] = merge(l, r->ch[]);
         return r->maintain(), r;
     }
 }

 typedef pair<Node *, Node *> pnn;
 pnn split(Node *o, int k) {
     if(o == null) return pnn(null, null);
     pnn res; o->down();
     if(o->ch[]->sz >= k) {
         res = split(o->ch[], k);
         o->ch[] = res.second;
         res.second = o;
     }else {
         res = split(o->ch[], k - o->ch[]->sz - );
         o->ch[] = res.first;
         res.first = o;
     }
     return o->maintain(), res;
 }

 pair<int, int> p[ + ];

 int main() {
 #ifdef DEBUG
     freopen("in.txt", "r", stdin);
     freopen("out.txt", "w", stdout);
 #endif

     int r, c, n;
     scanf("%d%d%d", &r, &c, &n);
     for(int i = ; i < n; i++) {
         scanf("%d%d", &p[i].first, &p[i].second);
     }
     sort(p, p + n);

     pis = pool, null = new Node();
     null->sz = ;
     Node *root = null;
     for(int i = ; i <= c; i++) {
         root = merge(root, new Node());
     }

     LL ans = S(r) * S(c);
     for(int i = , j = ; i <= r; i++) {
         root->add();
         while(j < n && p[j].first == i) {
             int x = p[j++].second;
             pnn r1 = split(root, x - );
             pnn r2 = split(r1.second, );
             r2.first->h = ;
             root = merge(merge(r1.first, r2.first), r2.second);
         }
         ans -= root->ans + S(root->sz) * root->h;
     }
     cout << ans << endl;

     return ;
 }

fhq treap

谁说一定要用fhq treap？

用普通的treap就好了 而且常数小！

注意建树最好$O(n)$建一下，每次insert有可能退化成$O(n^2)$的。

 #include<cstdio>
 #include<cstring>
 #include<cstdlib>
 #include<algorithm>
 #include<iostream>

 using namespace std;

 template<typename Q> Q &read(Q &x) {
     static char c, f;
     for(f = ; c = getchar(), !isdigit(c); ) if(c == '-') f = ;
     for(x = ; isdigit(c); c = getchar()) x = x *  + c - '';
     if(f) x = -x; return x;
 }
 template<typename Q> Q read() {
     static Q x; read(x); return x;
 }

 typedef long long LL;
 const int N =  + ;

 LL S(LL x) {
     return x * (x + ) >> ;
 }

 struct Node *null, *pis, *bin[N];
 int top;
 struct Node {
     int sz, v, h, tag;
     LL ans;
     Node *ch[];

     Node() {}
     Node(int v, int h) : v(v), h(h) {
         sz = , ans = tag = ;
         ch[] = ch[] = null;
     }

     void add(int d) {
         if(this == null) return;
         h += d, tag += d;
     }

     void maintain() {
         sz = ch[]->sz + ch[]->sz + ;
         ans = ;
         for(int c = ; c < ; c++) {
             ans += ch[c]->ans + S(ch[c]->sz) * (ch[c]->h - h);
         }
     }

     void down() {
         ch[]->add(tag);
         ch[]->add(tag);
         tag = ;
     }

     void *operator new(size_t) {
         return top ? bin[--top] : pis++;
     }

     void operator delete(void *p) {
         bin[top++] = (Node *) p;
     }

     int cmp(int x) const {
         if(x == v) return -;
         return x < v ?  : ;
     }
 }pool[N];

 void rotate(Node *&o, int d) {
     Node *t = o->ch[d];
     o->ch[d] = t->ch[d ^ ];
     t->ch[d ^ ] = o;
     o->maintain();
     (o = t)->maintain();
 }

 void modify(Node *&o, int x, int w) {
     o->down();
     int d = o->cmp(x);
     if(d == -) return o->h = w, o->maintain(), void();
     modify(o->ch[d], x, w);
     if(o->ch[d]->h < o->h) rotate(o, d);
     else o->maintain();
 }

 pair<int, int> p[ + ];

 void build(Node *&o, int l, int r) {
     if(l > r) return;
     int mid = (l + r) >> ;
     o = new Node(mid, );
     build(o->ch[], l, mid - );
     build(o->ch[], mid + , r);
     o->maintain();
 }

 int main() {
 #ifdef DEBUG
     freopen("in.txt", "r", stdin);
     freopen("out.txt", "w", stdout);
 #endif

     int r, c, n;
     scanf("%d%d%d", &r, &c, &n);
     for(int i = ; i < n; i++) {
         read(p[i].first), read(p[i].second);
     }
     sort(p, p + n);

     pis = pool, null = new Node(, );
     null->sz = ;
     Node *root;
     build(root, , c);

     LL ans = S(r) * S(c);
     for(int i = , j = ; i <= r; i++) {
         root->add();
         while(j < n && p[j].first == i) {
             modify(root, p[j++].second, );
         }
         ans -= root->ans + S(root->sz) * root->h;
     }
     cout << ans << endl;

     return ;
 }

普通treap