UVA 12657 Boxes in a Line

题目链接：https://vjudge.net/problem/UVA-12657

题目大意

　　你有n个盒子在桌子上的一条线上从左到右编号为1……n。你的任务是模拟四种操作

1. X Y 移动盒子编号X到盒子编号Y的左边（如果X已经在Y的左边了就忽略）
2. X Y 移动盒子编号X到盒子编号Y的右边（如果X已经在Y的右边了就忽略）
3. X Y 交换盒子编号X与盒子编号Y的位置
4. 将整条线反转

　　操作保证合法，X不等于Y

　　举一个例子，如果n=6，操作 1 1 4然后就变成了2 3 1 4 5 6；再操作 2 3 5就变成了 2 1 4 5 3 6；再操作 3 1 6 就变成 2 6 4 5 3 1；最后操作4，就变成了 1 3 5 4 6 2

　　输入

　　　　最多有10组数据，每个数据会包含两个整数n,m（1≤n,m<100,000）, 接下来是m行数据，表示操作。

　　输出

　　　　对于每组数据，输出他们奇数位置的编号的和。

　　翻译搬运自洛谷。

分析

　　静态链表模板题。

代码如下

#include <bits/stdc++.h>
using namespace std;
 
#define INIT() ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define Rep(i,n) for (int i = 0; i < (n); ++i)
#define For(i,s,t) for (int i = (s); i <= (t); ++i)
#define rFor(i,t,s) for (int i = (t); i >= (s); --i)
#define ForLL(i, s, t) for (LL i = LL(s); i <= LL(t); ++i)
#define rForLL(i, t, s) for (LL i = LL(t); i >= LL(s); --i)
#define foreach(i,c) for (__typeof(c.begin()) i = c.begin(); i != c.end(); ++i)
#define rforeach(i,c) for (__typeof(c.rbegin()) i = c.rbegin(); i != c.rend(); ++i)
 
#define pr(x) cout << #x << " = " << x << "  "
#define prln(x) cout << #x << " = " << x << endl
 
#define LOWBIT(x) ((x)&(-x))
 
#define ALL(x) x.begin(),x.end()
#define INS(x) inserter(x,x.begin())
 
#define ms0(a) memset(a,0,sizeof(a))
#define msI(a) memset(a,inf,sizeof(a))
#define msM(a) memset(a,-1,sizeof(a))

#define MP make_pair
#define PB push_back
#define ft first
#define sd second
 
template<typename T1, typename T2>
istream &operator>>(istream &in, pair<T1, T2> &p) {
    in >> p.first >> p.second;
    return in;
}
 
template<typename T>
istream &operator>>(istream &in, vector<T> &v) {
    for (auto &x: v)
        in >> x;
    return in;
}
 
template<typename T1, typename T2>
ostream &operator<<(ostream &out, const std::pair<T1, T2> &p) {
    out << "[" << p.first << ", " << p.second << "]" << "
";
    return out;
}

inline int gc(){
    static const int BUF = 1e7;
    static char buf[BUF], *bg = buf + BUF, *ed = bg;
    
    if(bg == ed) fread(bg = buf, 1, BUF, stdin);
    return *bg++;
} 

inline int ri(){
    int x = 0, f = 1, c = gc();
    for(; c<48||c>57; f = c=='-'?-1:f, c=gc());
    for(; c>47&&c<58; x = x*10 + c - 48, c=gc());
    return x*f;
}
 
typedef long long LL;
typedef unsigned long long uLL;
typedef pair< double, double > PDD;
typedef pair< int, int > PII;
typedef pair< string, int > PSI;
typedef set< int > SI;
typedef vector< int > VI;
typedef vector< VI > VVI;
typedef vector< PII > VPII;
typedef map< int, int > MII;
typedef multimap< int, int > MMII;
typedef unordered_map< int, int > uMII;
typedef pair< LL, LL > PLL;
typedef vector< LL > VL;
typedef vector< VL > VVL;
typedef priority_queue< int > PQIMax;
typedef priority_queue< int, VI, greater< int > > PQIMin;
const double EPS = 1e-10;
const LL inf = 0x7fffffff;
const LL infLL = 0x7fffffffffffffffLL;
const LL mod = 1e9 + 7;
const int maxN = 1e5 + 7;
const LL ONE = 1;
const LL evenBits = 0xaaaaaaaaaaaaaaaa;
const LL oddBits = 0x5555555555555555;

struct StaticList{
    int sl[maxN], nt[maxN], pv[maxN];
    int *next = nt, *prev = pv;
    int sz;
    
    void init(int x) {
        sz = x;
        For(i, 0, sz) {
            if(i) sl[i] = i;
            prev[i] = (sz + i) % (sz + 1);
            next[i] = (i + 1) % (sz + 1);
        }
    }
    
    // 把 x 插到 y 前面 
    void move(int x, int y) {
        if(y == x || next[x] == y) return;
        next[prev[x]] = next[x];
        prev[next[x]] = prev[x];
        
        next[prev[y]] = x;
        prev[x] = prev[y];
        next[x] = y;
        prev[y] = x;
    }
    
    void Swap(int x, int y) {
        // 如果两个节点相邻，要单独讨论 
        if(next[x] == y || prev[x] == y) {
            if(prev[x] == y) swap(x, y);
            swap(next[prev[x]], prev[next[y]]);
            next[x] = next[y];
            prev[y] = prev[x];
            prev[x] = y;
            next[y] = x;
            return;
        }
        
        swap(next[prev[x]], next[prev[y]]);
        swap(prev[next[x]], prev[next[y]]);
        swap(prev[x], prev[y]);
        swap(next[x], next[y]);
    }
    
    void reverse(){
        swap(prev, next);
    }
    
    LL getAns() {
        LL ret = 0;
        int p = next[0];
        
        while(p != 0) {
            ret += sl[p];
            p = next[p];
            if(p == 0) break;
            p = next[p];
        }
        
        return ret;
    }
    
    void print() {
        cout << "SL:  ";
        For(i, 0, sz) cout << " " << sl[i];
        cout << endl;
        
        cout << "prev:";
        For(i, 0, sz) cout << " " << prev[i];
        cout << endl;
        
        cout << "next:";
        For(i, 0, sz) cout << " " << next[i];
        cout << endl;
        
    }
}SL;

int n, m, T;

int main(){
    //freopen("MyOutput.txt","w",stdout);
    INIT();
    while(cin >> n >> m) {
        ++T;
        SL.init(n);
        Rep(i, m) {
            int t, x, y;
            cin >> t;
            if(t == 4) SL.reverse();
            else {
                cin >> x >> y;
                switch(t) {
                    case 1:{
                        SL.move(x, y);
                        break;
                    }
                    case 2:{
                        SL.move(x, SL.next[y]);
                        break;
                    }
                    case 3:{
                        SL.Swap(x, y);
                        break;
                    }
                }
            }
            //SL.print();
        }
        //SL.print();
        cout << "Case " << T << ": " << SL.getAns() << endl;
    }
    return 0;
}