Codeforces 696E ...Wait for it...(树链剖分)
题目链接 ...Wait for it...
考虑树链剖分。
对于树上的每个点开一个set,记录当前该节点上所有的girls。
每个节点初始的权值为set中的最小值。
询问的时候每次在路径上寻找最小值,并返回这个点的编号。
然后把这个点的set的第一个元素取出,换成下一个元素。
因为女孩总数不超过1e5,所以总查询次数不会超过1e5
修改操作用lazy标记就可以了。
#include <bits/stdc++.h> using namespace std; #define rep(i, a, b) for (int i(a); i <= (b); ++i) #define dec(i, a, b) for (int i(a); i >= (b); --i) #define lson i << 1, L, mid #define rson i << 1 | 1, mid + 1, R #define ls i << 1 #define rs i << 1 | 1 #define MP make_pair #define fi first #define se second typedef long long LL; typedef pair <LL, int> PII; const int N = 1e5 + 10; const LL inf = 1e18; int n, m, q; int id, cnt = 0; int ret[N]; int at[N], sz[N], son[N], top[N], f[N], in[N], out[N], deep[N], father[N]; vector <int> v[N]; set <PII> s[N]; LL lazy[N << 2]; PII t[N << 2]; void dfs(int x, int fa, int dep){ sz[x] = 1; son[x] = 0; father[x] = fa; deep[x] = dep; for (auto u : v[x]){ if (u == fa) continue; dfs(u, x, dep + 1); sz[x] += sz[u]; if (sz[son[x]] < sz[u]) son[x] = u; } } void dfs2(int x, int tp){ top[x] = tp; in[x] = f[x] = ++id; if (son[x]) dfs2(son[x], tp); for (auto u : v[x]){ if (u == father[x] || u == son[x]) continue; dfs2(u, u); } out[x] = id; } void pushup(int i){ t[i] = min(t[ls], t[rs]); } void pushdown(int i){ if (lazy[i]){ lazy[ls] += lazy[i]; lazy[rs] += lazy[i]; t[ls].fi += lazy[i]; t[rs].fi += lazy[i]; lazy[i] = 0; } } void build(int i, int L, int R){ lazy[i] = 0; if (L == R){ t[i] = *s[L].begin(); return; } int mid = (L + R) >> 1; build(lson); build(rson); pushup(i); } void update(int i, int L , int R , int l, int r, LL val){ if (l <= L && R <= r){ lazy[i] += val; t[i].fi += val; return; } pushdown(i); int mid = (L + R) >> 1 ; if (l <= mid) update(lson, l, r, val); if (r > mid) update(rson, l, r, val); pushup(i); } void modify(int i, int L, int R, int x){ if (L == R){ s[L].erase(s[L].begin()); t[i] = *s[L].begin(); t[i].fi += lazy[i]; return; } pushdown(i); int mid = (L + R) >> 1 ; if (x <= mid) modify(lson, x) ; else modify(rson, x); pushup(i); } PII query(int i, int L, int R, int l, int r){ if (l <= L && R <= r) return t[i]; pushdown(i); int mid = (L + R) >> 1 ; if (r <= mid) return query(lson, l, r); if (l > mid) return query(rson, l, r); return min(query(lson, l, r), query(rson, l, r)); } int Query(int x, int y){ PII ans = PII(inf, 0); while (top[x] ^ top[y]){ if (deep[top[x]] < deep[top[y]]) swap(x, y); ans = min(ans, query(1, 1, n, f[top[x]], f[x])); x = father[top[x]]; } if (deep[x] > deep[y]) swap(x, y); ans = min(ans, query(1, 1, n, f[x], f[y])); return ans.se; } int main(){ scanf("%d%d%d", &n, &m, &q); rep(i, 2, n){ int x, y; scanf("%d%d", &x, &y); v[x].push_back(y); v[y].push_back(x); } dfs(1, 0, 0); dfs2(1, 1); rep(i, 1, n) s[i].insert(MP(inf, 0)); at[0] = N - 1; rep(i, 1, m){ int x; scanf("%d", &x); at[i] = x; s[f[x]].insert(MP(i, i)); } build(1, 1, n); while (q--){ int op, x, y, lim; LL val; scanf("%d", &op); if (op == 2){ scanf("%d%lld", &x, &val); update(1, 1, n, in[x], out[x], val); } else{ scanf("%d%d%d", &x, &y, &lim); cnt = 0; while (lim--){ int idx = Query(x, y); if (idx == 0) break; ret[++cnt] = idx; modify(1, 1, n, f[at[idx]]); } printf("%d", cnt); rep(i, 1, cnt) printf(" %d", ret[i]); putchar(10); } } return 0; }