LG P4146 序列终结者
\(\text{Problem}\)
支持区间加区间翻转区间最大值
\(\text{Solution}\)
\(\text{FHQ-Treap}\) 两个标记加与翻转
然后维护区间最大值
\(\text{Code}\)
#include
#include
#include
#define re register
using namespace std;
const int N = 5e4 + 5;
int n, m, rt;
int ls[N], rs[N], mx[N], val[N], siz[N], tag1[N], tag2[N], rnd[N];
inline void read(int &x)
{
x = 0; int f = 1; char ch = getchar();
while (ch < '0' || ch > '9') f = (ch == '-' ? -1 : f), ch = getchar();
while (ch >= '0' && ch <= '9') x = (x << 3) + (x << 1) + ch - '0', ch = getchar();
x *= f;
}
inline int new_node(int v)
{
static int size = 0;
val[++size] = v, mx[size] = v, siz[size] = 1, rnd[size] = rand(),
ls[size] = rs[size] = tag1[size] = tag2[size] = 0;
return size;
}
inline void pushup(int p)
{
siz[p] = siz[ls[p]] + siz[rs[p]] + 1, mx[p] = val[p];
if (ls[p]) mx[p] = max(mx[p], mx[ls[p]]);
if (rs[p]) mx[p] = max(mx[p], mx[rs[p]]);
}
inline void pushdown(int p)
{
if (!p) return;
if (tag1[p])
{
if (ls[p]) tag1[ls[p]] += tag1[p], mx[ls[p]] += tag1[p], val[ls[p]] += tag1[p];
if (rs[p]) tag1[rs[p]] += tag1[p], mx[rs[p]] += tag1[p], val[rs[p]] += tag1[p];
tag1[p] = 0;
}
if (tag2[p])
{
tag2[p] = 0, swap(ls[p], rs[p]);
if (ls[p]) tag2[ls[p]] ^= 1;
if (rs[p]) tag2[rs[p]] ^= 1;
}
}
void split(int p, int k, int &x, int &y)
{
if (!p) return void(x = y = 0);
pushdown(p);
if (k <= siz[ls[p]]) y = p, split(ls[p], k, x, ls[y]);
else x = p, split(rs[p], k - siz[ls[p]] - 1, rs[x], y);
pushup(p);
}
int merge(int x, int y)
{
if (!x || !y) return x | y;
pushdown(x), pushdown(y);
if (rnd[x] < rnd[y]){rs[x] = merge(rs[x], y), pushup(x); return x;}
ls[y] = merge(x, ls[y]), pushup(y); return y;
}
int main()
{
srand((unsigned)time(NULL));
read(n), read(m);
for(re int i = 1; i <= n; i++) rt = merge(rt, new_node(0));
for(re int i = 1, op, l, r, ad, x, y, u, v; i <= m; i++)
{
read(op), read(l), read(r);
split(rt, r, x, y), split(x, l - 1, u, v);
if (op == 1) read(ad), tag1[v] += ad, mx[v] += ad, val[v] += ad;
else if (op == 2) tag2[v] ^= 1;
else printf("%d\n", mx[v]);
rt = merge(merge(u, v), y);
}
}