BZOJ3673 可持久化并查集 by zky

[Solution]

It's said that it's a very classic problem, although I don't know what the correct solution is.

My solution is to use treap to take the place of vector to make it persistent.

Very ugly...

[code]#include <cstdio>
#include <cstdlib>
#include <memory.h>
#include <algorithm>

using namespace std;

#ifdef WIN32
#define getRand() ((rand() << 16) | rand())
#else
#define getRand() rand()
#endif

const int maxa = 20009;
const int maxn = maxa * 40;

int n, m, ls[maxn], rs[maxn], sz[maxn], vl[maxn], w[maxn], rt[maxa], tn;

int newNode(int v0) {
int p = ++ tn;
ls[p] = 0;
rs[p] = 0;
sz[p] = 1;
vl[p] = v0;
w[p] = getRand();
return p;
}

inline void update(const int& x) {
sz[x] = sz[ls[x]] + sz[rs[x]] + 1;
}

int merge(int p, int q) {
if (!p)
return q;
else if (!q)
return p;
else if (w[p] > w[q]) {
rs[p] = merge(rs[p], q);
update(p);
return p;
}
else {
ls[q] = merge(p, ls[q]);
update(q);
return q;
}
}

int valOn(int p, int p0) {
if (sz[ls[p]] + 1 == p0)
return vl[p];
else if (sz[ls[p]] >= p0)
return valOn(ls[p], p0);
else
return valOn(rs[p], p0 - sz[ls[p]] - 1);
}

int changeNew(int p, int p0, int v0) {
int q = ++ tn;
vl[q] = vl[p];
ls[q] = ls[p];
rs[q] = rs[p];
sz[q] = sz[p];
if (sz[ls[p]] + 1 == p0)
vl[q] = v0;
else if (sz[ls[p]] >= p0)
ls[q] = changeNew(ls[p], p0, v0);
else
rs[q] = changeNew(rs[p], p0 - sz[ls[p]] - 1, v0);
update(q);
return q;
}

int getRoot(int c, int x) {
int r0 = valOn(rt[c], x);
if (r0 == x)
return r0;
else {
int rx = getRoot(c, r0);
return rx;
}
}

int main() {
#ifndef ONLINE_JUDGE
freopen("in.txt", "r", stdin);
freopen("o1.txt", "w", stdout);
#endif

srand(12093409);
scanf("%d%d", &n, &m);
tn = 0;
rt[0] = 0;
for (int i = 1; i <= n; i ++)
rt[0] = merge(rt[0], newNode(i));
for (int i = 0; i < m; i ++) {
int opt, x, y;
scanf("%d", &opt);
if (opt == 1) {
scanf("%d%d", &x, &y);
x = getRoot(i, x);
y = getRoot(i, y);
if (rand() & 1)
rt[i + 1] = changeNew(rt[i], x, y);
else
rt[i + 1] = changeNew(rt[i], y, x);
}
else if (opt == 2) {
int k;
scanf("%d", &k);
rt[i + 1] = rt[k];
}
else if (opt == 3) {
int x, y;
scanf("%d%d", &x, &y);
x = getRoot(i, x);
y = getRoot(i, y);
if (x == y)
printf("1\n");
else
printf("0\n");
rt[i + 1] = rt[i];
}
}
}