洛谷P1501 Tree II

LCT

还是LCT的板子，下放标记和那道线段树2一样，先放乘。。之前用char忘记getchar，调了好久。。。
注意开long long！！

#include <bits/stdc++.h>
#define INF 0x3f3f3f3f
#define full(a, b) memset(a, b, sizeof a)
using namespace std;
typedef long long ll;
inline int lowbit(int x){ return x & (-x); }
inline int read(){
    int X = 0, w = 0; char ch = 0;
    while(!isdigit(ch)) { w |= ch == '-'; ch = getchar(); }
    while(isdigit(ch)) X = (X << 3) + (X << 1) + (ch ^ 48), ch = getchar();
    return w ? -X : X;
}
inline int gcd(int a, int b){ return a % b ? gcd(b, a % b) : b; }
inline int lcm(int a, int b){ return a / gcd(a, b) * b; }
template<typename T>
inline T max(T x, T y, T z){ return max(max(x, y), z); }
template<typename T>
inline T min(T x, T y, T z){ return min(min(x, y), z); }
template<typename A, typename B, typename C>
inline A fpow(A x, B p, C lyd){
    A ans = 1;
    for(; p; p >>= 1, x = 1LL * x * x % lyd)if(p & 1)ans = 1LL * x * ans % lyd;
    return ans;
}
const ll N = 200005;
ll n, q, tot, p, ch[N][2], size[N], rev[N], val[N], fa[N], sum[N], mul[N], add[N], st[N];

void newNode(ll v){
    val[++tot] = v; size[tot] = mul[tot] = 1, sum[tot] = v;
    ch[tot][0] = ch[tot][1] = fa[tot] = rev[tot] = add[tot] = 0;
}

bool isRoot(ll x){
    return (ch[fa[x]][0] != x && ch[fa[x]][1] != x);
}

void pushMul(ll x, ll c){
    mul[x] *= c, add[x] *= c, sum[x] *= c, val[x] *= c;
    mul[x] %= p, add[x] %= p, sum[x] %= p, val[x] %= p;
}

void pushAdd(ll x, ll c){
    add[x] += c, sum[x] += size[x] * c, val[x] += c;
    add[x] %= p, sum[x] %= p, val[x] %= p;
}

void pushRev(ll x){
    rev[x] ^= 1, swap(ch[x][0], ch[x][1]);
}

void push_up(ll x){
    size[x] = size[ch[x][0]] + size[ch[x][1]] + 1;
    sum[x] = (sum[ch[x][0]] + sum[ch[x][1]] + val[x]) % p;
}

void push_down(ll x){
    ll l = ch[x][0], r = ch[x][1];
    if(mul[x] != 1){
        if(l) pushMul(l, mul[x]);
        if(r) pushMul(r, mul[x]);
    }
    if(add[x]){
        if(l) pushAdd(l, add[x]);
        if(r) pushAdd(r, add[x]);
    }
    if(rev[x]){
        if(l) pushRev(l);
        if(r) pushRev(r);
    }
    mul[x] = 1, add[x] = 0, rev[x] = 0;
}

void rotate(ll x){
    ll y = fa[x], z = fa[y], p = (ch[y][1] == x) ^ 1;
    push_down(y), push_down(x);
    ch[y][p^1] = ch[x][p], fa[ch[x][p]] = y;
    if(!isRoot(y)) ch[z][ch[z][1] == y] = x;
    fa[x] = z, fa[y] = x, ch[x][p] = y;
    push_up(y), push_up(x);
}

void splay(ll x){
    ll pos = 0; st[++pos] = x;
    for(ll i = x; !isRoot(i); i = fa[i]) st[++pos] = fa[i];
    while(pos) push_down(st[pos--]);
    while(!isRoot(x)){
        ll y = fa[x], z = fa[y];
        if(!isRoot(y)){
            if((ch[y][0] == x) ^ (ch[z][0] == y)) rotate(x);
            else rotate(y);
        }
        rotate(x);
    }
    push_up(x);
}

void access(ll x){
    for(ll pre = 0; x; pre = x, x = fa[x])
        splay(x), ch[x][1] = pre, push_up(x);
}

void makeRoot(ll x){
    access(x), splay(x), pushRev(x);
}

void split(ll x, ll y){
    makeRoot(x), access(y), splay(y);
}

ll findRoot(ll x){
    access(x), splay(x);
    while(ch[x][0]) x = ch[x][0];
    splay(x);
    return x;
}

void link(ll x, ll y){
    makeRoot(x);
    if(findRoot(y) != x) fa[x] = y;
    push_up(y);
}

void cut(ll x, ll y){
    makeRoot(x);
    if(findRoot(y) == x && fa[y] == x && !ch[y][0]){
        fa[y] = ch[x][1] = 0, push_up(x);
    }
}

int main(){

    p = 51061;
    scanf("%lld%lld", &n, &q);
    for(int i = 1; i <= n; i ++) newNode(1);
    for(int i = 1; i <= n - 1; i ++){
        ll u, v; scanf("%lld%lld", &u, &v);
        link(u, v);
    }
    while(q --){
        char ch[10]; scanf("%s", &ch);
        if(ch[0] == '+'){
            ll u, v; scanf("%lld%lld", &u, &v);
            ll c; scanf("%lld", &c);
            split(u, v), pushAdd(v, c);
        }
        else if(ch[0] == '-'){
            ll u, v; scanf("%lld%lld", &u, &v);
            ll x, y; scanf("%lld%lld", &x, &y);
            cut(u, v), link(x, y);
        }
        else if(ch[0] == '*'){
            ll u, v; scanf("%lld%lld", &u, &v);
            ll c; scanf("%lld", &c);
            split(u, v), pushMul(v, c);
        }
        else if(ch[0] == '/'){
            ll u, v; scanf("%lld%lld", &u, &v);
            split(u, v);
            printf("%lld\n", sum[v] % p);
        }
    }
    return 0;
}