注意
自己理解着打了一遍，注意两个点跳跃的时候，是比较两个点对应链顶的深度
#include <algorithm> #include <iterator> #include <iostream> #include <cstring> #include <cstdlib> #include <iomanip> #include <bitset> #include <cctype> #include <cstdio> #include <string> #include <vector> #include <stack> #include <cmath> #include <queue> #include <list> #include <map> #include <set> #include <cassert> /* ⊂_ヽ ＼＼ Λ＿Λ 来了老弟 ＼('ㅅ') > ⌒ヽ / へ＼ / / ＼＼ ﾚ ノ ヽ_つ / / / /| ( (ヽ | |、＼ | 丿 ＼ ⌒) | | ) / 'ノ ) Lﾉ */ using namespace std; #define lson (l , mid , rt << 1) #define rson (mid + 1 , r , rt << 1 | 1) #define debug(x) cerr << #x << " = " << x << " "; #define pb push_back #define pq priority_queue typedef long long ll; typedef unsigned long long ull; //typedef __int128 bll; typedef pair<ll ,ll > pll; typedef pair<int ,int > pii; typedef pair<int,pii> p3; //priority_queue<int> q;//这是一个大根堆q //priority_queue<int,vector<int>,greater<int> >q;//这是一个小根堆q #define fi first #define se second //#define endl ' ' #define boost ios::sync_with_stdio(false);cin.tie(0) #define rep(a, b, c) for(int a = (b); a <= (c); ++ a) #define max3(a,b,c) max(max(a,b), c); #define min3(a,b,c) min(min(a,b), c); const ll oo = 1ll<<17; const ll mos = 0x7FFFFFFF; //2147483647 const ll nmos = 0x80000000; //-2147483648 const int inf = 0x3f3f3f3f; const ll inff = 0x3f3f3f3f3f3f3f3f; //18 const ll mod = 2147483648; const double esp = 1e-8; const double PI=acos(-1.0); const double PHI=0.61803399; //黄金分割点 const double tPHI=0.38196601; template<typename T> inline T read(T&x){ x=0;int f=0;char ch=getchar(); while (ch<'0'||ch>'9') f|=(ch=='-'),ch=getchar(); while (ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar(); return x=f?-x:x; } inline void cmax(int &x,int y){if(x<y)x=y;} inline void cmax(ll &x,ll y){if(x<y)x=y;} inline void cmin(int &x,int y){if(x>y)x=y;} inline void cmin(ll &x,ll y){if(x>y)x=y;} /*-----------------------showtime----------------------*/ const int maxn = 1e6+9; int n,m,R,P; int a[maxn]; vector<int>mp[maxn]; int dp[maxn],fa[maxn],son[maxn],sz[maxn]; void dfs1(int u,int f, int deep){ int mx = 0; dp[u] = deep; sz[u] = 1; fa[u] = f; for(int i=0; i<mp[u].size(); i++){ int v = mp[u][i]; if(f == v) continue; dfs1(v, u, deep + 1); sz[u] += sz[v]; if(sz[v] > mx) son[u] = v, mx = sz[v]; } } int b[maxn]; int id[maxn],top[maxn]; int cnt = 0; void dfs2(int u,int f,int topf){ id[u] = ++cnt; top[u] = topf; b[cnt] = a[u]; if(son[u]) dfs2(son[u], u, topf); for(int i=0; i<mp[u].size(); i++){ int v = mp[u][i]; if(f == v || son[u] == v) continue; dfs2(v, u, v); } } int sum[maxn<<2],lazy[maxn<<2]; void build(int l,int r,int rt){ if(l == r){ sum[rt] = b[l]; return; } int mid = (l + r) >> 1; build(l, mid, rt<<1); build(mid+1,r,rt<<1|1); sum[rt] = (sum[rt<<1] + sum[rt<<1|1]) % P; } void pushdown(int l,int r,int rt){ int mid = (l + r) >> 1; lazy[rt<<1] = (lazy[rt<<1] + lazy[rt])%P; lazy[rt<<1|1] = (lazy[rt<<1|1] + lazy[rt])%P; sum[rt<<1] = (sum[rt<<1] + (mid - l+1) * lazy[rt])%P; sum[rt<<1|1] = (sum[rt<<1|1] + (r - mid)*lazy[rt]) %P; lazy[rt] = 0; } void update(int L,int R, int val, int l,int r,int rt){ if(l >= L && r<=R){ lazy[rt] =(lazy[rt] + val)%P; sum[rt] = (sum[rt] + (r - l + 1) * val)%P; return; } int mid = (l + r)>>1; if(lazy[rt]) pushdown(l,r,rt); if(mid >= L) update(L,R,val, l,mid,rt<<1); if(mid < R) update(L,R,val, mid+1,r,rt<<1|1); sum[rt] = (sum[rt<<1] + sum[rt<<1|1])%P; } int query(int L,int R,int l, int r,int rt){ if(l>=L && r<=R){ return sum[rt]; } int res = 0; int mid = (l + r)>>1; if(lazy[rt]) pushdown(l, r, rt); if(mid >= L) res = (res + query(L,R,l,mid,rt<<1)) %P; if(mid < R) res = (res + query(L,R,mid+1,r,rt<<1|1)) %P; sum[rt] = (sum[rt<<1] + sum[rt<<1|1])%P; return res; } void add1(int x,int y,int z){ while(top[x] != top[y]){ if(dp[top[x]] < dp[top[y]]) swap(x, y); update(id[top[x]], id[x], z, 1, n, 1); x = fa[top[x]]; } if(dp[x] > dp[y]) swap(x, y); update(id[x], id[y], z, 1, n, 1); } int getsum1(int x,int y) { int res = 0; while(top[x] != top[y]){ if(dp[top[x]] < dp[top[y]]) swap(x, y); res = (res + query(id[top[x]], id[x], 1, n, 1))%P; x = fa[top[x]]; } if(dp[x] > dp[y]) swap(x, y); res = (res + query(id[x], id[y], 1, n, 1))%P; return res; } void add2(int x,int z){ update(id[x], id[x] + sz[x] - 1, z, 1, n, 1); } int getsum2(int x){ return query(id[x], id[x] + sz[x] - 1, 1, n, 1); } int main(){ scanf("%d%d%d%d", &n, &m, &R, &P); rep(i, 1, n) scanf("%d", &a[i]); rep(i, 1, n-1){ int u,v; scanf("%d%d", &u, &v); mp[u].pb(v); mp[v].pb(u); } dfs1(R, R, 1); dfs2(R, R, R); build(1, n, 1); while(m --){ int op; scanf("%d", &op); if(op == 1) { int x, y, z; scanf("%d%d%d", &x, &y, &z); add1(x, y, z); } else if(op == 2) { int x, y; scanf("%d%d", &x, &y); printf("%d ", getsum1(x, y)); } else if(op == 3) { int x,z; scanf("%d%d", &x, &z); add2(x, z); } else if(op == 4){ int x; scanf("%d", &x); printf("%d ", getsum2(x)); } } return 0; }