Uva11987-almost Union-find (and check whether the set is deleted)

Uva11987-almost Union-find (and check whether the set is deleted)

Question Link

Here are three operations: 1 p q indicates that the set of the two numbers p q is merged. 2 p q indicates that the number of P is taken out from the original set and put into the set where Q is located. 3 P indicates the total number of elements and the number of elements in the set where p is queried.

Solution: query the set. Only the operations that are not deleted in the check set. Therefore, we need to reduce the impact of the deleted vertex to 0, that is, apply for a new ID for the deleted vertex. In the future, this new ID will be used to represent this vertex, in this way, the point P in the original set is meaningless, and the natural impact is 0.

Code:

#include <cstdio>#include <cstring>const int maxn = 2e5 + 5;int n, m;int parent[maxn], cnt[maxn], sum[maxn];int id[maxn];int dex;void init () {    for (int i = 0; i <= n; i++) {        cnt[i] = 1;        sum[i] = id[i] = parent[i] = i;    }    dex = n;}int getParent (int a) {    return a == parent[a] ? a: parent[a] = getParent (parent[a]);}void Union (int a, int b) {    int p = getParent (a);    int q = getParent (b);    if (p != q) {        parent[p] = q;        cnt[q] += cnt[p];        sum[q] += sum[p];    }}void move (int a) {    int p = getParent (id[a]);    cnt[p]--;    sum[p] -= a;    id[a] = ++dex;    parent[dex] = dex;    cnt[dex] = 1;    sum[dex] = a;  }int main () {    int type;    int a, b;    while (scanf ("%d%d", &n, &m) != EOF) {        init();        while (m--) {            scanf ("%d", &type);            if (type == 1) {                scanf ("%d%d", &a, &b);                Union (id[a], id[b]);            } else if (type == 2) {                scanf ("%d%d", &a, &b);                int p = getParent (id[a]);                int q = getParent (id[b]);                if (p != q) {                    move(a);                    Union(id[a], id[b]);                }            } else {                scanf ("%d", &a);                int p = getParent (id[a]);                printf ("%d %d\n", cnt[p], sum[p]);            }        }    }    return 0;}

Uva11987-almost Union-find (and check whether the set is deleted)