首页 > 代码库 > HDU 3966 Aragorn's Story(树链抛分)
HDU 3966 Aragorn's Story(树链抛分)
HDU Aragorn‘s Story
题目链接
树抛入门裸题,这题是区间修改单点查询,于是套树状数组就OK了
代码:
#include <cstdio> #include <cstring> #include <vector> #include <algorithm> using namespace std; const int N = 50005; inline int lowbit(int x) {return x&(-x);} int dep[N], fa[N], son[N], sz[N], top[N], id[N], idx; vector<int> g[N]; int bit[N]; int n, m, p, val[N]; void dfs1(int u, int f, int d) { dep[u] = d; sz[u] = 1; fa[u] = f; son[u] = 0; for (int i = 0; i < g[u].size(); i++) { int v = g[u][i]; if (v == f) continue; dfs1(v, u, d + 1); sz[u] += sz[v]; if (sz[son[u]] < sz[v]) son[u] = v; } } void dfs2(int u, int tp) { id[u] = ++idx; top[u] = tp; if (son[u]) dfs2(son[u], tp); for (int i = 0; i < g[u].size(); i++) { int v = g[u][i]; if (v == fa[u] || v == son[u]) continue; dfs2(v, v); } } void add(int x, int v) { while (x < N) { bit[x] += v; x += lowbit(x); } } void add(int l, int r, int v) { add(l, v); add(r + 1, -v); } void gao(int u, int v, int w) { int tp1 = top[u], tp2 = top[v]; while (tp1 != tp2) { if (dep[tp1] < dep[tp2]) { swap(tp1, tp2); swap(u, v); } add(id[tp1], id[u], w); u = fa[tp1]; tp1 = top[u]; } if (dep[u] > dep[v]) swap(u, v); add(id[u], id[v], w); } int query(int x) { int ans = 0; while (x) { ans += bit[x]; x -= lowbit(x); } return ans; } int main() { while (~scanf("%d%d%d", &n, &m, &p)) { idx = 0; memset(bit, 0, sizeof(bit)); for (int i = 1; i <= n; i++) { scanf("%d", &val[i]); g[i].clear(); } int u, v; while (m--) { scanf("%d%d", &u, &v); g[u].push_back(v); g[v].push_back(u); } dfs1(1, -1, 1); dfs2(1, 1); for (int i = 1; i <= n; i++) add(id[i], id[i], val[i]); char q[2]; int a, b, c; while (p--) { scanf("%s", q); if (q[0] == 'I' || q[0] == 'D') { scanf("%d%d%d", &a, &b, &c); if (q[0] == 'D') c = -c; gao(a, b, c); } else { scanf("%d", &a); printf("%d\n", query(id[a])); } } } return 0; }
HDU 3966 Aragorn's Story(树链抛分)
声明:以上内容来自用户投稿及互联网公开渠道收集整理发布,本网站不拥有所有权,未作人工编辑处理,也不承担相关法律责任,若内容有误或涉及侵权可进行投诉: 投诉/举报 工作人员会在5个工作日内联系你,一经查实,本站将立刻删除涉嫌侵权内容。