HDU 5044 Tree（树链剖分）

Posted 2020-09-30 llguanli

HDU 5044 Tree

php?

field=problem&key=2014+ACM%2FICPC+Asia+Regional+Shanghai+Online&source=1&searchmode=source" target="_blank" style="">题目链接

就简单的树链剖分，只是坑要加输入外挂，还要手动扩栈

代码：

#include <cstdio>
#include <cstring>
#include <vector>
#include <algorithm>
using namespace std;

const int N = 100005;

#pragma comment(linker, "/STACK:1024000000,1024000000")

void scanf_(int &num) {
	char in;
	bool neg=false;
	while(((in=getchar()) > '9' || in<'0') && in!='-') ;
	if(in=='-')
	{
		neg=true;
		while((in=getchar()) >'9' || in<'0');
	}
	num=in-'0';
	while(in=getchar(),in>='0'&&in<='9')
		num*=10,num+=in-'0';
	if(neg)
		num=0-num;
}

int dep[N], fa[N], son[N], sz[N], top[N], id[N], idx, val[N];
int first[N], next[N * 2], vv[N * 2], en;
int bit[2][N];

void init() {
	en = 0;
	idx = 0;
	memset(first, -1, sizeof(first));
	memset(bit, 0, sizeof(bit));
}

void add_Edge(int u, int v) {
	vv[en] = v;
	next[en] = first[u];
	first[u] = en++;
}

void dfs1(int u, int f, int d) {
	dep[u] = d;
	sz[u] = 1;
	fa[u] = f;
	son[u] = 0;
	for (int i = first[u]; i + 1; i = next[i]) {
		int v = vv[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 = first[u]; i + 1; i = next[i]) {
		int v = vv[i];
		if (v == fa[u] || v == son[u]) continue;
		dfs2(v, v);
	}
}

inline int lowbit(int x) {
	return x&(-x);
}

void add(int ty, int x, int v) {
	while (x < N) {
		bit[ty][x] += v;
		x += lowbit(x);
	}
}

void add(int ty, int l, int r, int v) {
	add(ty, l, v);
	add(ty, r + 1, -v);
}

int get(int ty, int x) {
	int ans = 0;
	while (x) {
		ans += bit[ty][x];
		x -= lowbit(x);
	}
	return ans;
}

void gao(int ty, 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(ty, id[tp1], id[u], w);
		u = fa[tp1];
		tp1 = top[u];
	}
	if (dep[u] > dep[v]) swap(u, v);
	if (ty == 1) {
		if (u != v)
			add(ty, id[son[u]], id[v], w);
	} else add(ty, id[u], id[v], w);
}

int T, n, m, s[N], t[N];

int main() {
	int cas = 0;
	scanf("%d", &T);
	while (T--) {
		init();
		scanf("%d%d", &n, &m);
		for (int i = 1; i < n; i++) {
			scanf_(s[i]); scanf_(t[i]);
			add_Edge(s[i], t[i]);
			add_Edge(t[i], s[i]);
		}
		dfs1(1, 0, 1);
		dfs2(1, 1);
		for (int i = 1; i < n; i++) {
			if (dep[s[i]] < dep[t[i]])
				swap(s[i], t[i]);
		}
		char Q[10];
		int u, v, k;
		while (m--) {
			scanf("%s", Q);
			scanf_(u); scanf_(v); scanf_(k);
			if (Q[3] == '1') gao(0, u, v, k);
			else gao(1, u, v, k);
		}
		printf("Case #%d:\n", ++cas);
		for (int i = 1; i <= n; i++)
			printf("%d%c", get(0, id[i]), i == n ? '\n' : ' ');
		for (int i = 1; i < n; i++)
			printf("%d%c", get(1, id[s[i]]), i == n - 1 ? '\n' : ' ');
		if (n == 1) printf("\n");
	}
	return 0;
}