【POJ 3580】 SuperMemo

【题目链接】

点击打开链接

【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+];
string opt;

template <typename T> inline void read(T &x) {
        int f=; x=;
        char c = getchar();
        for (; !isdigit(c); c = getchar()) { if (c == '-') f = -f; }
        for (; isdigit(c); c = getchar()) x = x *  + c - '';
        x *= f;
}

template <typename T> inline void write(T x) {
    if (x < ) { putchar('-'); x = -x; }
    if (x > ) write(x/);
    putchar(x%+'');
}

template <typename T> inline void writeln(T x) {
    write(x);
    puts("");
}

struct Splay {
        int root,total;
        struct Node {
                int fa,son[],size,add,Min,val;
                bool rev;
        } Tree[MAXN*+];
        inline bool get(int x) {
                return Tree[Tree[x].fa].son[] == x;
        }
        inline void build(int index,int l,int r) {
                int mid = (l + r) >> ;
                Tree[index].size = ;
                Tree[index].add = Tree[index].rev = ;
                Tree[index].val = Tree[index].Min = a[mid];
                if (l == r) return;
                if (l < mid) {
                        ++total;
                        Tree[index].son[] = total;
                        Tree[total].fa = index;
                        build(total,l,mid-);
                        Tree[index].size += Tree[Tree[index].son[]].size;
                        Tree[index].Min = min(Tree[index].Min,Tree[Tree[index].son[]].Min);
                }
                if (mid < r) {
                        ++total;
                        Tree[index].son[] = total;
                        Tree[total].fa = index;
                        build(total,mid+,r);
                        Tree[index].size += Tree[Tree[index].son[]].size;
                        Tree[index].Min = min(Tree[index].Min,Tree[Tree[index].son[]].Min);
                }
        }
        inline void new_node(int index,int x,int f) {
                Tree[index].rev = ;
                Tree[index].size = ;
                Tree[index].val = Tree[index].Min = x;
                Tree[index].add = ;
                Tree[index].fa = f;
                Tree[index].son[] = Tree[index].son[] = ;
        }
        inline int query_pos(int x) {
                int index = root;
                while (true) {
                        pushdown(index);
                        if (x > Tree[Tree[index].son[]].size) {
                                x -= Tree[Tree[index].son[]].size;
                                if (x == ) return index;
                                --x;
                                index = Tree[index].son[];
                        } else index = Tree[index].son[];
                }
        }
        inline void pushdown(int index) {
                if (Tree[index].rev) {
                        swap(Tree[index].son[],Tree[index].son[]);
                        Tree[Tree[index].son[]].rev ^= ;
                        Tree[Tree[index].son[]].rev ^= ;
                        Tree[index].rev = ;
                }
                if (Tree[index].add) {
                        Tree[Tree[index].son[]].val += Tree[index].add;
                        Tree[Tree[index].son[]].val += Tree[index].add;
                        Tree[Tree[index].son[]].add += Tree[index].add;
                        Tree[Tree[index].son[]].add += Tree[index].add;
                        Tree[Tree[index].son[]].Min += Tree[index].add;
                        Tree[Tree[index].son[]].Min += Tree[index].add;
                        Tree[index].add = ;
                }
        }
        inline void update(int index) {
                Tree[index].size = Tree[Tree[index].son[]].size + Tree[Tree[index].son[]].size + ;
                Tree[index].Min = Tree[index].val;
                if (Tree[index].son[]) Tree[index].Min = min(Tree[index].Min,Tree[Tree[index].son[]].Min);
                if (Tree[index].son[]) Tree[index].Min = min(Tree[index].Min,Tree[Tree[index].son[]].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^];
                if (Tree[x].son[tmpx^]) Tree[Tree[x].son[tmpx^]].fa = f;
                Tree[x].son[tmpx^] = 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+);
                splay(x,); splay(y,root);
                new_node(++total,val,Tree[root].son[]);
                Tree[Tree[root].son[]].son[] = total;
                update(Tree[root].son[]);
                update(root);
        }
        inline void erase(int p) {
                int x = query_pos(p-),
                        y = query_pos(p+);
                splay(x,); splay(y,root);
                Tree[Tree[root].son[]].son[] = ;
                update(Tree[root].son[]);
                update(root);
        }
        inline void add(int l,int r,int v) {
                int x = query_pos(l-),
                        y = query_pos(r+);
                splay(x,); splay(y,root);
                Tree[Tree[Tree[root].son[]].son[]].val += v;
                Tree[Tree[Tree[root].son[]].son[]].add += v;
                Tree[Tree[Tree[root].son[]].son[]].Min += v;
                update(Tree[root].son[]);
                update(root);
        }
        inline void reverse(int l,int r) {
                int x = query_pos(l-),
                        y = query_pos(r+);
                splay(x,); splay(y,root);
                Tree[Tree[Tree[root].son[]].son[]].rev ^= ;
        }
        inline int query_min(int l,int r) {
                int x = query_pos(l-),
                        y = query_pos(r+);
                splay(x,); splay(y,root);
                return Tree[Tree[Tree[root].son[]].son[]].Min;
        }
        inline void revolve(int l,int r,int t) {
                int x = query_pos(r-t),
                        y = query_pos(r+);
                splay(x,); splay(y,root);
                int tmp = Tree[Tree[root].son[]].son[];
                Tree[Tree[root].son[]].son[] = ;
                update(Tree[root].son[]);
                update(root);
                x = query_pos(l-);
                y = query_pos(l);
                splay(x,); splay(y,root);
                Tree[Tree[root].son[]].son[] = tmp;
                Tree[tmp].fa = Tree[root].son[];
                update(Tree[root].son[]);
                update(root);
        }
} T;

int main() {

        read(N);

        T.root = T.total = ;
        for (i = ; i <= N + ; i++) read(a[i]);
        a[] = a[N+] = INF;
        T.build(,,N+);

        read(M);
        while (M--) {
                cin >> opt;
                if (opt[] == 'A') {
                        read(x); read(y); read(d);
                        if (x > y) swap(x,y);
                        T.add(x+,y+,d);
                } else if (opt[] == 'R' && opt[] == 'E' && opt[] == 'V' && opt[] == 'E'){
                        read(x); read(y);
                        if (x > y) swap(x,y);
                        T.reverse(x+,y+);
                } else if (opt[] == 'R' && opt[] == 'E' && opt[] == 'V' && opt[] == 'O') {
                        read(x); read(y); read(t);
                        if (x > y) swap(x,y);
                        t = (t % (y - x + ) + y - x + ) % (y - x + );
                        if (!t) continue;
                        T.revolve(x+,y+,t);
                } else if (opt[] == 'I') {
                        read(x); read(P);
                        T.Insert(x+,P);
                } else if (opt[] == 'D') {
                        read(x);
                        T.erase(x+);
                } else if (opt[] == 'M') {
                        read(x); read(y);
                        if (x > y) swap(x,y);
                        writeln(T.query_min(x+,y+));
                }
        }

        return ;

}