ACM模版
伸展数
/*
* 伸展树(Splay Tree)
* 题目:维修数列。
* 经典题,插入、删除、修改、翻转、求和、求和最大的子序列
*/
const int MAXN = 500010;
const int INF = 0x3f3f3f3f;
int pre[MAXN], ch[MAXN][2], key[MAXN], size[MAXN];
int root, tot1;
int sum[MAXN], rev[MAXN], same[MAXN];
int lx[MAXN], rx[MAXN], mx[MAXN];
int s[MAXN], tot2; // 内存池和容量
int a[MAXN];
int n, q;
// debug Start**********************************
void Treavel(int x)
{
if (x)
{
Treavel(ch[x][0]);
printf("结点:%2d: 左儿子 %2d 右儿子 %2d 父结点 %2d size = %2d\n", x, ch[x][0], ch[x][1], pre[x], size[x]);
Treavel(ch[x][1]);
}
return ;
}
void debug()
{
printf("root:%d\n", root);
Treavel(root);
return ;
}
// debug End***********************************
void NewNode(int &r, int father, int k)
{
if (tot2)
{
r = s[tot2--]; // 取的时候是tot2--,存的时候就是++tot2
}
else
{
r = ++tot1;
}
pre[r] = father;
ch[r][0] = ch[r][1] = 0;
key[r] = k;
sum[r] = k;
rev[r] = same[r] = 0;
lx[r] = rx[r] = mx[r] = k;
size[r] = 1;
return ;
}
void Update_Rev(int r)
{
if (!r)
{
return ;
}
swap(ch[r][0], ch[r][1]);
swap(lx[r], rx[r]);
rev[r] ^= 1;
return ;
}
void Update_Same(int r, int v)
{
if (!r)
{
return ;
}
key[r] = v;
sum[r] = v * size[r];
lx[r] = rx[r] = mx[r] = max(v, v * size[r]);
same[r] = 1;
return ;
}
void push_up(int r)
{
int lson = ch[r][0], rson = ch[r][1];
size[r] = size[lson] + size[rson] + 1;
sum[r] = sum[lson] + sum[rson] + key[r];
lx[r] = max(lx[lson], sum[lson] + key[r] + max(0, lx[rson]));
rx[r] = max(rx[rson], sum[rson] + key[r] + max(0, rx[lson]));
mx[r] = max(0, rx[lson]) + key[r] + max(0, lx[rson]);
mx[r] = max(mx[r], max(mx[lson], mx[rson]));
return ;
}
void push_down(int r)
{
if (same[r])
{
Update_Same(ch[r][0], key[r]);
Update_Same(ch[r][1], key[r]);
same[r] = 0;
}
if(rev[r])
{
Update_Rev(ch[r][0]);
Update_Rev(ch[r][1]);
rev[r] = 0;
}
return ;
}
void Build(int &x, int l, int r, int father)
{
if (l > r)
{
return ;
}
int mid = (l + r) / 2;
NewNode(x, father, a[mid]);
Build(ch[x][0], l, mid - 1, x);
Build(ch[x][1], mid + 1, r, x);
push_up(x);
return ;
}
void Init()
{
root = tot1 = tot2 = 0;
ch[root][0] = ch[root][1] = size[root] = pre[root] = 0;
same[root] = rev[root] = sum[root] = key[root] = 0;
lx[root] = rx[root] = mx[root] = -INF;
NewNode(root, 0, -1);
NewNode(ch[root][1], root, -1);
for (int i = 0; i < n; i++)
{
scanf("%d", &a[i]);
}
Build(Key_value, 0, n - 1, ch[root][1]);
push_up(ch[root][1]);
push_up(root);
}
// 旋转,0为左旋,1为右旋
void Rotate(int x,int kind)
{
int y = pre[x];
push_down(y);
push_down(x);
ch[y][!kind] = ch[x][kind];
pre[ch[x][kind]] = y;
if (pre[y])
ch[pre[y]][ch[pre[y]][1]==y] = x;
pre[x] = pre[y];
ch[x][kind] = y;
pre[y] = x;
push_up(y);
}
// Splay调整,将r结点调整到goal下面
void Splay(int r, int goal)
{
push_down(r);
while (pre[r] != goal)
{
if (pre[pre[r]] == goal)
{
push_down(pre[r]);
push_down(r);
Rotate(r, ch[pre[r]][0] == r);
}
else
{
push_down(pre[pre[r]]);
push_down(pre[r]);
push_down(r);
int y = pre[r];
int kind = ch[pre[y]][0] == y;
if (ch[y][kind] == r)
{
Rotate(r, !kind);
Rotate(r, kind);
}
else
{
Rotate(y, kind);
Rotate(r, kind);
}
}
}
push_up(r);
if (goal == 0)
{
root = r;
}
return ;
}
int Get_kth(int r, int k)
{
push_down(r);
int t = size[ch[r][0]] + 1;
if (t == k)
{
return r;
}
if (t > k)
{
return Get_kth(ch[r][0], k);
}
else
{
return Get_kth(ch[r][1], k - t);
}
}
// 在第pos个数后面插入tot个数
void Insert(int pos, int tot)
{
for (int i = 0; i < tot; i++)
{
scanf("%d",&a[i]);
}
Splay(Get_kth(root, pos + 1), 0);
Splay(Get_kth(root, pos + 2), root);
Build(Key_value, 0, tot - 1, ch[root][1]);
push_up(ch[root][1]);
push_up(root);
return ;
}
// 删除子树
void erase(int r)
{
if (!r)
{
return ;
}
s[++tot2] = r;
erase(ch[r][0]);
erase(ch[r][1]);
return ;
}
// 从第pos个数开始连续删除tot个数
void Delete(int pos, int tot)
{
Splay(Get_kth(root, pos), 0);
Splay(Get_kth(root, pos + tot + 1), root);
erase(Key_value);
pre[Key_value] = 0;
Key_value = 0;
push_up(ch[root][1]);
push_up(root);
return ;
}
// 将从第pos个数开始的连续的tot个数修改为c
void Make_Same(int pos, int tot, int c)
{
Splay(Get_kth(root, pos), 0);
Splay(Get_kth(root, pos + tot + 1), root);
Update_Same(Key_value, c);
push_up(ch[root][1]);
push_up(root);
return ;
}
// 将第pos个数开始的连续tot个数进行反转
void Reverse(int pos, int tot)
{
Splay(Get_kth(root, pos), 0);
Splay(Get_kth(root,pos+tot + 1), root);
Update_Rev(Key_value);
push_up(ch[root][1]);
push_up(root);
return ;
}
// 得到第pos个数开始的tot个数的和
int Get_Sum(int pos, int tot)
{
Splay(Get_kth(root, pos), 0);
Splay(Get_kth(root, pos + tot + 1), root);
return sum[Key_value];
}
// 得到第pos个数开始的tot个数中最大的子段和
int Get_MaxSum(int pos, int tot)
{
Splay(Get_kth(root, pos), 0);
Splay(Get_kth(root, pos + tot + 1), root);
return mx[Key_value];
}
void InOrder(int r)
{
if (!r)
{
return ;
}
push_down(r);
InOrder(ch[r][0]);
printf("%d ",key[r]);
InOrder(ch[r][1]);
return ;
}
int main()
{
// freopen("in.txt", "r", stdin);
// freopen("out.txt", "w", stdout);
while (scanf("%d%d", &n, &q) == 2)
{
Init();
char op[20];
int x, y, z;
while (q--)
{
scanf("%s", op);
if (strcmp(op, "INSERT") == 0)
{
scanf("%d%d", &x, &y);
Insert(x, y);
}
else if (strcmp(op, "DELETE") == 0)
{
scanf("%d%d", &x, &y);
Delete(x,y);
}
else if (strcmp(op, "MAKE-SAME") == 0)
{
scanf("%d%d%d", &x, &y, &z);
Make_Same(x, y, z);
}
else if (strcmp(op, "REVERSE") == 0)
{
scanf("%d%d", &x, &y);
Reverse(x, y);
}
else if (strcmp(op, "GET-SUM") == 0)
{
scanf("%d%d", &x, &y);
printf("%d\n", Get_Sum(x, y));
}
else if (strcmp(op, "MAX-SUM") == 0)
{
printf("%d\n", Get_MaxSum(1, size[root] - 2));
}
}
}
return 0;
}