HDU 3487 Play with Chain

HDU_3487

    拿这个题目练了一下splay的区间的切割，也就是删除、移动、添加一个连续的区间。

#include<stdio.h>
#include<string.h>
#define MAXD 300010
int N, M, T, node, size[MAXD], rev[MAXD], left[MAXD], right[MAXD], pre[MAXD], key[MAXD], ans[MAXD], P;
void newnode(int &cur, int k)
{
    cur = ++ node;
    key[cur] = k;
    size[cur] = 1;
    rev[cur] = 0;
    left[cur] = right[cur] = 0;
}
void update(int cur)
{
    size[cur] = size[left[cur]] + size[right[cur]] + 1;
}
void pushdown(int cur)
{
    if(rev[cur])
    {
        int ls = left[cur], rs = right[cur];
        rev[ls] = (rev[ls] + 1) & 1, rev[rs] = (rev[rs] + 1) & 1;
        left[cur] = rs, right[cur] = ls;
        rev[cur] = 0;
    }
}
void build(int &cur, int x, int y, int p)
{
    int mid = (x + y) / 2;
    newnode(cur, mid);
    pre[cur] = p;
    if(x == y)
        return ;
    if(x < mid)
        build(left[cur], x, mid - 1, cur);
    if(mid < y)
        build(right[cur], mid + 1, y, cur);
    update(cur);
}
void init()
{
    T = node = size[0] = left[0] = right[0] = 0;
    newnode(T, 0), newnode(right[T], N + 1);
    size[T] = 2, pre[T] = 0, pre[right[T]] = T;
    build(left[right[T]], 1, N, right[T]);
    update(right[T]), update(T);
}
void leftrotate(int x)
{
    int y = right[x], p = pre[x];
    right[x] = left[y];
    if(right[x])
        pre[right[x]] = x;
    left[y] = x;
    pre[x] = y;
    pre[y] = p;
    if(p == 0)
        T = y;
    else
        right[p] == x ? right[p] = y : left[p] = y;
    update(x);
}
void rightrotate(int x)
{
    int y = left[x], p = pre[x];
    left[x] = right[y];
    if(left[x])
        pre[left[x]] = x;
    right[y] = x;
    pre[x] = y;
    pre[y] = p;
    if(p == 0)
        T = y;
    else
        right[p] == x ? right[p] = y : left[p] = y;
    update(x);
}
void splay(int x, int goal)
{
    int y, z;
    for(;;)
    {
        if((y = pre[x]) == goal)
            break;
        if((z = pre[y]) == goal)
            right[y] == x ? leftrotate(y) : rightrotate(y);
        else
        {
            if(right[z] == y)
            {
                if(right[y] == x)
                    leftrotate(z), leftrotate(y);
                else
                    rightrotate(y), leftrotate(z);
            }
            else
            {
                if(left[y] == x)
                    rightrotate(z), rightrotate(y);
                else
                    leftrotate(y), rightrotate(z);
            }
        }
    }
    update(x);
}
void rotateto(int k, int goal)
{
    int i = T;
    for(;;)
    {
        pushdown(i);
        if(k == size[left[i]] + 1)
            break;
        if(k <= size[left[i]])
            i = left[i];
        else
            k -= size[left[i]] + 1, i = right[i];
    }
    splay(i, goal);
}
void cut(int x, int y, int z)
{
    int k, t;
    rotateto(x, 0), rotateto(y + 2, T);
    t = left[right[T]];
    left[right[T]] = 0;
    update(right[T]), update(T);
    rotateto(z + 1, 0), rotateto(z + 2, T);
    pre[t] = right[T];
    left[right[T]] = t;
    update(right[T]), update(T);
}
void flip(int x, int y)
{
    int k;
    rotateto(x, 0), rotateto(y + 2, T);
    k = left[right[T]];
    rev[k] = (rev[k] + 1) & 1;
}
void solve()
{
    int i, x, y, z;
    char b[10];
    for(i = 0; i < M; i ++)
    {
        scanf("%s", b);
        if(b[0] == 'C')
        {
            scanf("%d%d%d", &x, &y, &z);
            cut(x, y, z);
        }
        else
        {
            scanf("%d%d", &x, &y);
            flip(x, y);
        }
    }
}
void dfs(int cur)
{
    pushdown(cur);
    if(left[cur])
        dfs(left[cur]);
    ans[P ++] = key[cur];
    if(right[cur])
        dfs(right[cur]);
}
void printresult()
{
    int i;
    P = 0;
    dfs(T);
    printf("%d", ans[1]);
    for(i = 2; i < P - 1; i ++)
        printf(" %d", ans[i]);
    printf("\n");
}
int main()
{
    while(scanf("%d%d", &N, &M) == 2)
    {
        if(N < 0 && M < 0)
            break;
        init();
        solve();
        printresult();
    }
    return 0;
}