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| # include <bits/stdc++.h>
const int mod = 201314;
const int MaxN = 100010;
struct edge
{
int next, to;
};
struct node
{
int l, r;
int sum, tag;
};
struct query
{
int r, z, id;
};
edge e[MaxN << 1];
query q[MaxN << 1];
int n, m, cnt, dfsnum;
int hson[MaxN], fa[MaxN], dfn[MaxN], ans[MaxN];
int head[MaxN], size[MaxN], dep[MaxN], top[MaxN];
struct SegmentTree
{
node t[MaxN << 2];
inline void pushup(int id){t[id].sum = t[id << 1].sum + t[id << 1 | 1].sum;}
inline void build(int id, int l, int r)
{
t[id].l = l, t[id].r = r;
if(l == r)
return;
int mid = (l + r) >> 1;
build(id << 1, l, mid);
build(id << 1 | 1, mid + 1, r);
}
inline void pushdown(int id)
{
if(t[id].tag)
{
t[id << 1].sum += t[id].tag * (t[id << 1].r - t[id << 1].l + 1);
t[id << 1 | 1].sum += t[id].tag * (t[id << 1 | 1].r - t[id << 1 | 1].l + 1);
t[id << 1].tag += t[id].tag;
t[id << 1 | 1].tag += t[id].tag;
t[id].tag = 0;
}
}
inline void modify(int id, int l, int r, int val)
{
if(t[id].l > r || t[id].r < l)
return;
if(l <= t[id].l && t[id].r <= r)
{
t[id].sum += val * (t[id].r - t[id].l + 1);
t[id].tag += val;
return;
}
pushdown(id);
modify(id << 1, l, r, val);
modify(id << 1 | 1, l, r, val);
pushup(id);
}
inline int query(int id, int l, int r)
{
if(t[id].l > r || t[id].r < l)
return 0;
if(l <= t[id].l && t[id].r <= r)
return t[id].sum;
pushdown(id);
return query(id << 1, l, r) + query(id << 1 | 1, l, r);
}
}T;
inline int cmp(query a, query b)
{
return a.r < b.r;
}
inline void add_edge(int u, int v)
{
++cnt;
e[cnt].to = v;
e[cnt].next = head[u];
head[u] = cnt;
}
inline void dfs1(int u, int f)
{
size[u] = 1;
for(int i = head[u]; i; i = e[i].next)
{
int v = e[i].to;
if(v == f)
continue;
dep[v] = dep[u] + 1;
fa[v] = u;
dfs1(v, u);
size[u] += size[v];
if(size[v] > size[hson[u]])
hson[u] = v;
}
}
inline void dfs2(int u, int Top)
{
++dfsnum;
dfn[u] = dfsnum;
top[u] = Top;
if(hson[u])
dfs2(hson[u], Top);
for(int i = head[u]; i; i = e[i].next)
{
int v = e[i].to;
if(v == fa[u] || v == hson[u])
continue;
dfs2(v, v);
}
}
inline void update_chain(int u, int v)
{
while(top[u] != top[v])
{
if(dep[top[u]] < dep[top[v]])
std::swap(u, v);
T.modify(1, dfn[top[u]], dfn[u], 1);
u = fa[top[u]];
}
if(dep[u] < dep[v])
std::swap(u, v);
T.modify(1, dfn[v], dfn[u], 1);
}
inline int query_chain(int u, int v)
{
int ans = 0;
while(top[u] != top[v])
{
if(dep[top[u]] < dep[top[v]])
std::swap(u, v);
ans += T.query(1, dfn[top[u]], dfn[u]);
u = fa[top[u]];
}
if(dep[u] < dep[v])
std::swap(u, v);
ans += T.query(1, dfn[v], dfn[u]);
return ans;
}
int main()
{
scanf("%d%d", &n, &m);
for(int i = 2; i <= n; i++)
{
int u;
scanf("%d", &u);
++u;
add_edge(i, u);
add_edge(u, i);
}
dep[1] = 1;
dfs1(1, 0), dfs2(1, 1);
T.build(1, 1, n);
for(int i = 1; i <= m; i++)
{
int l, r, z;
scanf("%d%d%d", &l, &r, &z);
l++, r++, z++;
q[i * 2 - 1] = (query){l - 1, z, i * 2 - 1};
q[i * 2] = (query){r, z, i * 2};
}
int now = 1;
std::sort(q + 1, q + 2 * m + 1, cmp);
for(int i = 1; i <= n; i++)
{
update_chain(1, i);
while(q[now].r < i)
++now;
while(q[now].r == i)
{
ans[q[now].id] = query_chain(1, q[now].z);
++now;
}
}
for(int i = 1; i <= m; i++)
printf("%d\n", (ans[i * 2] - ans[i * 2 - 1]) % mod);
return 0;
}
|