Graph and Queries hdu3762

这题用并查集+BST离线解决，编程实现是难点，这题使用动态内存分配比较方便，因为开始可能需要建很多的树，或者自己写一个内存回收类，调试过程很痛苦，RE到MLE再到一直RE，终于AC==。。。

#include <iostream>#include <cstdio>#include <cstdlib>#include <cmath>#include <queue>#include <algorithm>#include <vector>#include <cstring>#include <stack>#include <cctype>#include <utility>   #include <map>#include <string>  #include <climits> #include <set>#include <string>    #include <sstream>#include <utility>   #include <ctime>using std::priority_queue;using std::vector;using std::swap;using std::stack;using std::sort;using std::max;using std::min;using std::pair;using std::map;using std::string;using std::cin;using std::cout;using std::set;using std::queue;using std::string;using std::istringstream;using std::make_pair;using std::getline;using std::greater;using std::endl;using std::multimap;typedef long long LL;typedef unsigned long long ULL;typedef pair<int, int> PAIR;typedef multimap<int, int> MMAP;const int MAXN(40010);const int SIGMA_SIZE(82);const int MAXM(500010);const int MAXE(60010);const int MAXH(18);const int INFI((INT_MAX-1) >> 2);const int BASE(131);const int MOD(20071027);const ULL LIM(1000000000000000ull);template<typename T>struct NODE{NODE *ch[2];int r, s;T key;int cmp(const T &op) const{if(op == key) return -1;return op < key? 0: 1;}void maintain(){s = ch[0]->s+ch[1]->s+1;}};template<typename T>  //内存回收类struct POOL{typedef NODE<T> ND;ND pool[MAXN];ND *ind_p;ND *bump[MAXN];int ind_b;void init(){ind_p = pool;ind_b = 0;}ND *NEW(){return ind_b? bump[--ind_b]: ind_p++;}void FREE(ND *sour){bump[ind_b++] = sour;}};template<typename T>struct TREAP{typedef NODE<T> ND;static POOL<T> pool;static ND *NIL;ND *RT;T tkey;void init(){if(NIL == 0){pool.init();NIL = pool.NEW();NIL->ch[0] = NIL->ch[1] = NIL;NIL->s = 0;NIL->r = -1;}RT = NIL;}void rotate(ND *&sour, int f){ND *tp = sour->ch[f^1];sour->ch[f^1] = tp->ch[f];tp->ch[f] = sour;sour->maintain();tp->maintain();sour = tp;}void insert( T &value){tkey = value;insert_(RT);}void insert_(ND *&sour){if(sour == NIL){sour = pool.NEW();sour->ch[0] = sour->ch[1] = NIL;sour->key = tkey;sour->r = rand();sour->s = 1;}else{int f = (tkey < sour->key? 0: 1);insert_(sour->ch[f]);if(sour->ch[f]->r > sour->r)rotate(sour, f^1);sour->maintain();}}void remove(const T &value){tkey = value;remove_(RT);}void remove_(ND *&sour){int f = sour->cmp(tkey);if(f == -1){if(sour->ch[0] == NIL)pool.FREE(sour), sour = sour->ch[1];elseif(sour->ch[1] == NIL)pool.FREE(sour), sour = sour->ch[0];else{int f2 = (sour->ch[0]->r > sour->ch[1]->r? 1: 0);rotate(sour, f2);remove_(sour->ch[f2]);}}elseremove_(sour->ch[f]);if(sour != NIL)sour->maintain();}ND *find(const T &value){ND *sour = RT;while(sour != NIL){int f = sour->cmp(value);if(f == -1)break;sour = sour->ch[f];}return sour;}ND *select(int kth){ND *sour = RT;int tk;while(sour != NIL && kth != (tk = sour->ch[0]->s+1)){if(kth < tk)sour = sour->ch[0];else{kth -= tk;sour = sour->ch[1];}}return sour;}int rank(const T &value) //此出结果为左界{ND *sour = RT;int ret = 1;while(sour != NIL){if(value < sour->key) //如果此处改成<则求出的结果为右界+1sour = sour->ch[0];else{ret += sour->ch[0]->s+1;sour = sour->ch[1];}}return ret;}ND *pre(const T &value)  //返回小于value的最大元素的索引,否则返回NIL{tkey = value;return pre_(RT);}ND *pre_(ND *sour){if(sour == NIL)return NIL;if(tkey <= sour->key)return pre_(sour->ch[0]);else{ND *tp = pre_(sour->ch[1]);return tp == NIL? sour: tp;}}ND *suc(const T &value) //返回大于value的最小元素索引,否则返回NIL{tkey = value;return suc_(RT);}ND *suc_(ND *sour){if(sour == NIL)return NIL;if(tkey >= sour->key)return suc_(sour->ch[1]);else{ND *tp = suc_(sour->ch[0]);return tp == NIL? sour: tp;}}void merge(ND *&sour) //合并以sour为根节点的子树{if(sour == NIL)return;merge(sour->ch[0]);merge(sour->ch[1]);insert(sour->key);pool.FREE(sour);sour = NIL;   //一定要把sour置为NIL，不然爆栈}void removetree(ND *&sour) //删除以sour为根节点的子树{if(sour == NIL)return;removetree(sour->ch[0]);removetree(sour->ch[1]);pool.FREE(sour);sour = NIL;  //一定要把sour置为NIL，不然爆栈 }void debug(){printf("/****************************************/\n");debug_(RT, 0);printf("/****************************************/\n");}void debug_(ND *sour, int vec){if(sour == NIL)return;debug_(sour->ch[0], vec+1);for(int i = 0; i < vec; ++i)printf("     ");printf("%d\n", sour->key);debug_(sour->ch[1], vec+1);}};TREAP<int>::ND *TREAP<int>::NIL = 0;POOL<int> TREAP<int>::pool; struct FIND_SET{int fa[MAXN];int find(int sour){return sour == fa[sour]? sour: fa[sour] = find(fa[sour]);}};struct OP{char type;int op1, op2;};TREAP<int> trp[20010];FIND_SET fs;int weight[20010];OP arr[MAXM];int cnt;TREAP<int>::ND *NIL = TREAP<int>::NIL;int from[MAXE], to[MAXE];bool is_remove[MAXE];void add_edge(int ind){int u = fs.find(from[ind]), v = fs.find(to[ind]);if(u != v){if(trp[u].RT->s < trp[v].RT->s){fs.fa[u] = v;trp[v].merge(trp[u].RT);}else{fs.fa[v] = u;trp[u].merge(trp[v].RT);}}}int main(){int n, m, n_case(0);TREAP<int>::ND *tp;for(int i = 1; i <= 20000; ++i)trp[i].init();while(scanf("%d%d", &n, &m), n+m){for(int i = 1; i <= n; ++i)scanf("%d", weight+i);for(int i = 1; i <= m; ++i)scanf("%d%d", from+i, to+i);memset(is_remove, 0, sizeof(is_remove));cnt = 0;while(scanf(" %c", &arr[cnt].type), arr[cnt].type != 'E'){if(arr[cnt].type == 'D'){scanf("%d", &arr[cnt].op1);is_remove[arr[cnt].op1] = true;}elsescanf("%d%d", &arr[cnt].op1, &arr[cnt].op2);if(arr[cnt].type == 'C')swap(arr[cnt].op2, weight[arr[cnt].op1]);++cnt;}for(int i = 1; i <= n; ++i){trp[i].removetree(trp[i].RT);trp[i].init();trp[i].insert(weight[i]);fs.fa[i] = i;}for(int i = 1; i <= m; ++i)if(!is_remove[i])add_edge(i);double ans = 0;int ansi = 0;int tu;for(int i = cnt-1; i >= 0; --i){switch(arr[i].type){case 'D':add_edge(arr[i].op1);break;case 'Q':tu = fs.find(arr[i].op1);if(arr[i].op2 >= 1 && arr[i].op2 <= trp[tu].RT->s){tp = trp[tu].select(trp[tu].RT->s-arr[i].op2+1);ans += tp->key;}++ansi;break;case 'C':tu = fs.find(arr[i].op1);trp[tu].remove(weight[arr[i].op1]);trp[tu].insert(arr[i].op2);weight[arr[i].op1] = arr[i].op2;break;}}printf("Case %d: %.6f\n", ++n_case, ans/ansi);}return 0;}