hdu3487 Play with Chain

  1 #include <cstdio>
  2 #include <cstring>
  3 #include <algorithm>
  4 using namespace std;
  5 const int maxn = 3e5 + 10;
  6 int pre[maxn], ch[maxn][2], key[maxn], size[maxn];
  7 bool rev[maxn], ok;
  8 int n, m, nodes;
  9 int root;
 10 char buf[15];
 11 
 12 void new_node(int &u, int fa, int value){
 13     u = ++nodes;
 14     ch[u][0] = ch[u][1] = 0;
 15     key[u] = value;
 16     pre[u] = fa;
 17     size[u] = size[ch[u][0]] = size[ch[u][1]] = 0;
 18     rev[u] = 0;
 19 }
 20 
 21 void push_up(int u) { size[u] = 1 + size[ch[u][0]] + size[ch[u][1]]; }
 22 
 23 void build(int l, int r, int &u, int fa){
 24     if(r < l) return;
 25     int mid = (l + r) >> 1;
 26     new_node(u, fa, mid);
 27     build(l, mid - 1, ch[u][0], u);
 28     build(mid + 1, r, ch[u][1], u);
 29     push_up(u);
 30 }
 31 
 32 void push_down(int u){
 33     if(!size[u] || !rev[u]) return;
 34     rev[ch[u][0]] ^= 1;
 35     rev[ch[u][1]] ^= 1;
 36     swap(ch[u][0], ch[u][1]);
 37     rev[u] = 0;
 38 }
 39 
 40 void rotate(int u, int d){
 41     int y = pre[u];
 42     ch[y][!d] = ch[u][d];
 43     if(pre[y]) ch[pre[y]][ch[pre[y]][1] == y] = u;
 44     pre[ch[u][d]] = y;
 45     ch[u][d] = y;
 46     pre[u] = pre[y];
 47     pre[y] = u;
 48     push_up(y), push_up(u);
 49 }
 50 
 51 void splay(int u, int dest){
 52     while(pre[u] != dest){
 53         if(pre[pre[u]] == dest) { rotate(u, ch[pre[u]][0] == u); break; }
 54         int y = pre[u];
 55         int d = ch[pre[u]][0] == u;
 56         if(ch[pre[y]][d] == y) rotate(u, d), rotate(u, !d);
 57         else rotate(y, d), rotate(u, d);
 58     }
 59     if(!dest) root = u;
 60 }
 61 
 62 int get_kth(int u, int k){
 63     push_down(u);
 64     int tem = size[ch[u][0]];
 65     if(tem + 1 == k) return u;
 66     return tem >= k ? get_kth(ch[u][0], k) : get_kth(ch[u][1], k - tem - 1);
 67 }
 68 
 69 void reverse(int a, int b){
 70     int x = get_kth(root, a);
 71     int y = get_kth(root, b + 2);
 72     splay(x, 0);
 73     splay(y, root);
 74     rev[ch[y][0]] ^= 1;
 75 }
 76 
 77 void cut(int a, int b, int c){
 78     int x = get_kth(root, a);//get address
 79     int y = get_kth(root, b + 2);
 80     splay(x, 0);
 81     splay(y, root);
 82     int tem = ch[y][0];
 83     ch[ch[root][1]][0] = 0;
 84     push_up(ch[root][1]);
 85     push_up(root);//maintain size, cut interval[a,b]
 86     int z = get_kth(root, c + 1);
 87     splay(z, 0);
 88     int nex = get_kth(root, 2 + size[ch[root][0]]);
 89     splay(nex, root);
 90     pre[tem] = nex;//link
 91     ch[nex][0] = tem;
 92     push_up(nex);
 93     push_up(root);
 94 }
 95 
 96 void print(int u){
 97     if(!size[u]) return;
 98     push_down(u);
 99     print(ch[u][0]);
100     if(key[u] >= 1 && key[u] <= n) ok ? putchar(‘ ‘) : ok ^= 1, printf("%d", key[u]);
101     print(ch[u][1]);
102     push_up(u);
103 }
104 
105 int main(){
106     freopen("in.txt", "r", stdin);
107     while(~scanf("%d%d", &n, &m) && (n + 1)){
108         ok = nodes = 0;
109         pre[0] = ch[0][0] = ch[0][1] = size[0] = 0;//null node
110         build(0, n + 1, root, 0);
111         for(int i = 1, x, y, z; i <= m; i++){
112             scanf("%s%d%d", buf, &x, &y);
113             if(buf[0] == ‘C‘) scanf("%d", &z), cut(x, y, z);
114             else reverse(x, y);
115         }
116         print(root), putchar(‘\n‘);
117     }
118     return 0;
119 }