HDU 4441 Queue Sequence[Splay Tree]

/* * HDU 4441 Queue Sequence * Asia 2012 Tianjin K.Queue Sequence * 用平衡树做，不过我只会Splay，还不是很熟练。直接用了NOI2005维护数列的模板。 *  1.insert p  在p位置插入一个没在序列中的最小正整数，因为n<=1e5，我就用一个树状数组去找了，二分找到最小的正整数a；  然后插入a到p位置，还要插入-a，因为是队列，所以如果a之前有x个正整数，那么我们的-a就应该放在开始的x个负整数之后，要求-a尽量往右，那么我们找到第x+1个负整数的位置p_，然后插入到这个位置p_，因为可能没有第x+1负整数，所以注意特判。  2.remove i  把i和-i移除。我用一个数组记录i和-i对应的节点指针，删除时，先把节点splay到根，然后就能知道节点所在的序列位置，删除即可。  3. query i  求i和-i之间的数的和。跟remove一样，找到两数的位置后splay求和即可。  写得好悲催！中间找不出错误，自己不够细心了，精力不够，撸不起。  写了一个生成数据的程序，来验证自己的代码，老是程序崩溃，外加TLE。  后来才发现，是push_up写错了，%>_<% * */#include <cstdio>#include <cstring>#include <cassert>#include <algorithm>using namespace std;typedef long long int64;const int MAXN = 200000 + 5;struct TreeArray {int c[MAXN];#define lowbit(x) ((x)&(-x))void add(int i, int v) {for (; i < MAXN; i += lowbit(i)) {c[i] += v;}}int sum(int i) {int s = 0;for (; i > 0; i -= lowbit(i)) {s += c[i];}return s;}};struct SplayTree {struct Node {Node *ch[2], *pre;int sz, psz, nsz;int val;int64 sum;};#define keyTree (root->ch[1]->ch[0])Node *root, *null_node;Node mem[MAXN];Node *que[MAXN], *pool[MAXN];int mem_cnt, top;Node *vp[MAXN];int offset;void push_up(Node *x) {if (x == null_node) return;x->sz = 1;if (x->val > 0) {x->psz = 1, x->nsz = 0;} else if (x->val < 0) {x->psz = 0, x->nsz = 1;} else {x->psz = x->nsz = 0;}x->sum = x->val;for (int c = 0; c < 2; ++c) {if (x->ch[c] != null_node) {x->sz += x->ch[c]->sz;x->psz += x->ch[c]->psz;x->nsz += x->ch[c]->nsz;x->sum += x->ch[c]->sum;}}}/** 旋转操作，c=0表示左旋，逆时针，c=1表示右旋，顺时针 */void rotate(Node *x, int c) {Node *y = x->pre;y->ch[!c] = x->ch[c];if (x->ch[c] != null_node) x->ch[c]->pre = y;x->pre = y->pre;if (y->pre != null_node) y->pre->ch[ y == y->pre->ch[1] ] = x; x->ch[c] = y;y->pre = x;push_up(y);}/** 伸展的操作，将x节点转到f下，f要在x之上，f为null_node时表示x转为根 */void splay(Node *x, Node *f) {while (x->pre != f) {if (x->pre->pre == f) {rotate(x, x->pre->ch[0] == x);} else {Node *y = x->pre, *z = y->pre;bool c = (z->ch[0] == y);if (y->ch[c] == x) {rotate(x, !c);rotate(x, c);} else {rotate(y, c);rotate(x, c);}}}push_up(x);push_up(f);if (f == null_node) root = x;}bool select(int k, Node *f) {Node *x = root;for (;;) {int sz = x->ch[0]->sz;if (sz + 1 == k) break;if (k <= sz) {x = x->ch[0];} else {k -= sz + 1;x = x->ch[1];}if (x == null_node) {return false;}}splay(x, f);return true;}int size() const {return root->sz - 2;}Node* new_node(int val) {Node *x;if (top >= 0) x = pool[top--];else x = mem + mem_cnt++;memset(x, 0, sizeof(Node));x->pre = x->ch[0] = x->ch[1] = null_node;vp[val+offset] = x;x->sz = 1;if (val > 0) x->psz = 1;else if (val < 0) x->nsz = 1;x->val = x->sum = val;return x;}void init(int n) {memset(vp, 0, sizeof(vp));offset = n;null_node = mem;memset(null_node, 0, sizeof(Node));null_node->pre = null_node->ch[0] = null_node->ch[1] = null_node;mem_cnt = 1, top = -1;// 开头和末尾添加两个节点，避免特判，方便取区间，但是节点数变为n+2root = new_node(0);root->ch[1] = new_node(-2*n-1);root->ch[1]->pre = root;push_up(root);}/* 将 实际 [l,r] 区间转到 keyTree */void ch_key_tree(int l, int r) {select(l, null_node);select(r+2, root);}void erase(Node * &x) {if (x == null_node) {return;}Node *f = x->pre, **fr = que, **ta = que;*ta++ = x;while (fr < ta) {Node *x = *fr++;vp[x->val + offset] = NULL;pool[++top] = x;if (x->ch[0] != null_node) *ta++ = x->ch[0];if (x->ch[1] != null_node) *ta++ = x->ch[1];}x = null_node;push_up(f);}void del(int pos, int tot) {ch_key_tree(pos, pos+tot-1);erase(keyTree);push_up(root);}int64 get_sum(int l, int r) {ch_key_tree(l, r);return keyTree->sum;}void pre_ord(Node *x) {if (x == null_node) return;for (int i = 0; i < 2; ++i)if (x->ch[i] != null_node && x->ch[i]->pre != x) {fprintf(stderr, "error pre %d(%p)<-%d(%p)\n", x->val, x, x->ch[i]->val, x->ch[0]);exit(-1);}if (x->sz != 1 + x->ch[0]->sz + x->ch[1]->sz) {fprintf(stderr, "error sz %d:%d  %p %d\n", x->sz, 1+x->ch[0]->sz+x->ch[1]->sz, x, x->val);exit(-1);}if (x->ch[0]) pre_ord(x->ch[0]);printf("%d ", x->val);//printf("%d(%p)  ", x->val, x);if (x->ch[1]) pre_ord(x->ch[1]);}void travel() {printf("travel() ");pre_ord(root);printf("\n");}/******************** Problem Operation **********/int get_sz(int t, int v) {//printf("get_sz %d %d\n", v, v + offset);if (vp[v+offset] == NULL) {fprintf(stderr, "vp %d %d\n", v, v + offset);//while (1);assert(vp[v+offset]);}splay(vp[v+offset], null_node);if (t == 0) return root->ch[0]->sz;else if (t > 0) return root->ch[0]->psz + 1;else return root->ch[0]->nsz + 1;}int get_size(int t, int l, int r) {ch_key_tree(l, r);if (t == 0) return keyTree->sz;else if (t > 0) return keyTree->psz;else return keyTree->nsz;}void ins(int p, int v) {//printf("ins %d %d\n", p, v);ch_key_tree(p, p-1);keyTree = new_node(v);keyTree->pre = root->ch[1];push_up(root->ch[1]);push_up(root);}int loc_ne(int no) {int l = 1, r = size();while (l < r) {int m = (l + r) >> 1;int s = get_size(-1, 1, m);if (s < no) {l = m + 1;} else {r = m;}}if (get_size(-1, 1, l) < no) ++l;return l;}void rm(int v) {//if (vp[v+offset] == NULL) return;int l = get_sz(0, v);del(l, 1);}int64 query(int i) {if (vp[i+offset] == NULL || vp[-i+offset] == NULL) return -1;int l = get_sz(0, i), r = get_sz(0, -i);//printf("query %d %d\n", l, r);return get_sum(l, r);}};SplayTree spt;TreeArray ta;int get_minp() {int l = 1, r = MAXN - 1;while (l < r) {int m = (l + r) >> 1;if (ta.sum(m) >= 1) {r = m;} else {l = m + 1;}}return l;}int main() {int n, ncase = 0;while (EOF != scanf("%d", &n)) {++ncase;printf("Case #%d:\n", ncase);memset(ta.c, 0, sizeof(ta.c));for (int i = 1; i <= n; ++i) ta.add(i, 1);spt.init(n);for (int i = 0; i < n; ++i) {char cmd[32];int d;scanf("%s%d", cmd, &d);//fprintf(stderr, "%d:%s %d\n", i, cmd, d);if ('i' == cmd[0]) { // insert p++d;int a = get_minp();ta.add(a, -1);spt.ins(d, a); // insert +aint as = spt.get_sz(1, a);int p_ = spt.loc_ne(as);//printf("loc %d => %d\n", as, p_);spt.ins(p_, -a);} else if ('r' == cmd[0]) { // remove dspt.rm(-d);spt.rm(d);ta.add(d, 1);} else if ('q' == cmd[0]) { // query dprintf("%I64d\n", spt.query(d));} else {}//spt.travel(); puts("");}}return 0;}

生成数据的程序：

#include <cstdio>#include <cstring>#include <ctime>#include <set>using namespace std;template <const int MAXN>struct TreeArray {int c[MAXN];#define lowbit(x) ((x)&(-x))void add(int i, int v) {for (; i < MAXN; i += lowbit(i)) {c[i] += v;}}int sum(int i) {int s = 0;for (; i > 0; i -= lowbit(i)) {s += c[i];}return s;}int get_minp() {int l = 1, r = MAXN - 1;while (l < r) {int m = (l + r) >> 1;if (sum(m) >= 1) {r = m;} else {l = m + 1;}}return l;}};TreeArray<100005> ta;set<int> ss;void data(int n) {int len = 0;printf("%d\n", n);ss.clear();memset(ta.c, 0, sizeof(ta.c));for (int i = 1; i <= n; ++i) ta.add(i, 1);for (int i = 0; i < n; ++i) {int p = rand() % 3;if (p == 0 || len == 0) {printf("insert %d\n", rand() % (len+1));len += 2;int a = ta.get_minp();ta.add(a, -1);ss.insert(a);} else {int b = rand() % ss.size();set<int>::iterator it = ss.begin();for (int i = 1; i < b; ++i) ++it;if (p == 1) {printf("remove %d\n", *it);ta.add(*it, 1);ss.erase(it);len -= 2;} else {printf("query %d\n", *it);}}}}int main() {srand(time(0));data(100000);return 0;}