【POJ 3580】 SuperMemo
【题目链接】
【算法】
本题也是Splay区间操作的模板题，不过要比BZOJ 3223要稍微复杂一些，做完此题后，我终于对Splay有了更深入的理解，有“拨开云雾见青天”的感觉
本题还是有许多细节的，笔者花了5h才通过了此题
【代码】
#include <algorithm> #include <bitset> #include <cctype> #include <cerrno> #include <clocale> #include <cmath> #include <complex> #include <cstdio> #include <cstdlib> #include <cstring> #include <ctime> #include <deque> #include <exception> #include <fstream> #include <functional> #include <limits> #include <list> #include <map> #include <iomanip> #include <ios> #include <iosfwd> #include <iostream> #include <istream> #include <ostream> #include <queue> #include <set> #include <sstream> #include <stdexcept> #include <streambuf> #include <string> #include <utility> #include <vector> #include <cwchar> #include <cwctype> #include <stack> #include <limits.h> using namespace std; #define MAXN 100000 const int INF = 2e9; int i,N,M,d,P,x,y,t; int a[MAXN+10]; string opt; template <typename T> inline void read(T &x) { int f=1; x=0; char c = getchar(); for (; !isdigit(c); c = getchar()) { if (c == '-') f = -f; } for (; isdigit(c); c = getchar()) x = x * 10 + c - '0'; x *= f; } template <typename T> inline void write(T x) { if (x < 0) { putchar('-'); x = -x; } if (x > 9) write(x/10); putchar(x%10+'0'); } template <typename T> inline void writeln(T x) { write(x); puts(""); } struct Splay { int root,total; struct Node { int fa,son[2],size,add,Min,val; bool rev; } Tree[MAXN*2+10]; inline bool get(int x) { return Tree[Tree[x].fa].son[1] == x; } inline void build(int index,int l,int r) { int mid = (l + r) >> 1; Tree[index].size = 1; Tree[index].add = Tree[index].rev = 0; Tree[index].val = Tree[index].Min = a[mid]; if (l == r) return; if (l < mid) { ++total; Tree[index].son[0] = total; Tree[total].fa = index; build(total,l,mid-1); Tree[index].size += Tree[Tree[index].son[0]].size; Tree[index].Min = min(Tree[index].Min,Tree[Tree[index].son[0]].Min); } if (mid < r) { ++total; Tree[index].son[1] = total; Tree[total].fa = index; build(total,mid+1,r); Tree[index].size += Tree[Tree[index].son[1]].size; Tree[index].Min = min(Tree[index].Min,Tree[Tree[index].son[1]].Min); } } inline void new_node(int index,int x,int f) { Tree[index].rev = 0; Tree[index].size = 1; Tree[index].val = Tree[index].Min = x; Tree[index].add = 0; Tree[index].fa = f; Tree[index].son[0] = Tree[index].son[1] = 0; } inline int query_pos(int x) { int index = root; while (true) { pushdown(index); if (x > Tree[Tree[index].son[0]].size) { x -= Tree[Tree[index].son[0]].size; if (x == 1) return index; --x; index = Tree[index].son[1]; } else index = Tree[index].son[0]; } } inline void pushdown(int index) { if (Tree[index].rev) { swap(Tree[index].son[0],Tree[index].son[1]); Tree[Tree[index].son[0]].rev ^= 1; Tree[Tree[index].son[1]].rev ^= 1; Tree[index].rev = 0; } if (Tree[index].add) { Tree[Tree[index].son[0]].val += Tree[index].add; Tree[Tree[index].son[1]].val += Tree[index].add; Tree[Tree[index].son[0]].add += Tree[index].add; Tree[Tree[index].son[1]].add += Tree[index].add; Tree[Tree[index].son[0]].Min += Tree[index].add; Tree[Tree[index].son[1]].Min += Tree[index].add; Tree[index].add = 0; } } inline void update(int index) { Tree[index].size = Tree[Tree[index].son[0]].size + Tree[Tree[index].son[1]].size + 1; Tree[index].Min = Tree[index].val; if (Tree[index].son[0]) Tree[index].Min = min(Tree[index].Min,Tree[Tree[index].son[0]].Min); if (Tree[index].son[1]) Tree[index].Min = min(Tree[index].Min,Tree[Tree[index].son[1]].Min); } inline void splay(int x,int pos) { int f; for (f = Tree[x].fa; (f = Tree[x].fa) != pos; rotate(x)) { if (Tree[f].fa != pos) rotate(get(f) == get(x) ? (f) : (x)); } if (!pos) root = x; } inline void rotate(int x) { int f = Tree[x].fa,g = Tree[f].fa, tmpx = get(x),tmpf = get(f); pushdown(f); pushdown(x); if (!f) return; Tree[f].son[tmpx] = Tree[x].son[tmpx^1]; if (Tree[x].son[tmpx^1]) Tree[Tree[x].son[tmpx^1]].fa = f; Tree[x].son[tmpx^1] = f; Tree[f].fa = x; Tree[x].fa = g; if (g) Tree[g].son[tmpf] = x; update(f); update(x); } inline void Insert(int p,int val) { int x = query_pos(p), y = query_pos(p+1); splay(x,0); splay(y,root); new_node(++total,val,Tree[root].son[1]); Tree[Tree[root].son[1]].son[0] = total; update(Tree[root].son[1]); update(root); } inline void erase(int p) { int x = query_pos(p-1), y = query_pos(p+1); splay(x,0); splay(y,root); Tree[Tree[root].son[1]].son[0] = 0; update(Tree[root].son[1]); update(root); } inline void add(int l,int r,int v) { int x = query_pos(l-1), y = query_pos(r+1); splay(x,0); splay(y,root); Tree[Tree[Tree[root].son[1]].son[0]].val += v; Tree[Tree[Tree[root].son[1]].son[0]].add += v; Tree[Tree[Tree[root].son[1]].son[0]].Min += v; update(Tree[root].son[1]); update(root); } inline void reverse(int l,int r) { int x = query_pos(l-1), y = query_pos(r+1); splay(x,0); splay(y,root); Tree[Tree[Tree[root].son[1]].son[0]].rev ^= 1; } inline int query_min(int l,int r) { int x = query_pos(l-1), y = query_pos(r+1); splay(x,0); splay(y,root); return Tree[Tree[Tree[root].son[1]].son[0]].Min; } inline void revolve(int l,int r,int t) { int x = query_pos(r-t), y = query_pos(r+1); splay(x,0); splay(y,root); int tmp = Tree[Tree[root].son[1]].son[0]; Tree[Tree[root].son[1]].son[0] = 0; update(Tree[root].son[1]); update(root); x = query_pos(l-1); y = query_pos(l); splay(x,0); splay(y,root); Tree[Tree[root].son[1]].son[0] = tmp; Tree[tmp].fa = Tree[root].son[1]; update(Tree[root].son[1]); update(root); } } T; int main() { read(N); T.root = T.total = 1; for (i = 2; i <= N + 1; i++) read(a[i]); a[1] = a[N+2] = INF; T.build(1,1,N+2); read(M); while (M--) { cin >> opt; if (opt[0] == 'A') { read(x); read(y); read(d); if (x > y) swap(x,y); T.add(x+1,y+1,d); } else if (opt[0] == 'R' && opt[1] == 'E' && opt[2] == 'V' && opt[3] == 'E'){ read(x); read(y); if (x > y) swap(x,y); T.reverse(x+1,y+1); } else if (opt[0] == 'R' && opt[1] == 'E' && opt[2] == 'V' && opt[3] == 'O') { read(x); read(y); read(t); if (x > y) swap(x,y); t = (t % (y - x + 1) + y - x + 1) % (y - x + 1); if (!t) continue; T.revolve(x+1,y+1,t); } else if (opt[0] == 'I') { read(x); read(P); T.Insert(x+1,P); } else if (opt[0] == 'D') { read(x); T.erase(x+1); } else if (opt[0] == 'M') { read(x); read(y); if (x > y) swap(x,y); writeln(T.query_min(x+1,y+1)); } } return 0; }
