Luogu1501 Tree II - LCT

Code

 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #define rd read()
 #define ll long long
 using namespace std;

 const int N = 1e5 + ;
 const int mod = ;

 int n, m;

 int read() {
     int X = , p = ; char c = getchar();
     for (; c > '' || c < ''; c = getchar())
         if (c == '-') p = -;
     for (; c >= '' && c <= ''; c = getchar())
         X = X *  + c - '';
     return X * p;
 }

 namespace LCT {
     int ch[N][], tun[N], f[N], size[N];
     ll sum[N], val[N], tim[N], ad[N];
 #define lc(x) ch[x][0]
 #define rc(x) ch[x][1]
     int isroot(int x) {
         return lc(f[x]) != x && rc(f[x]) != x;
     }

     int get(int x) {
         return rc(f[x]) == x;
     }

     void up(int x) {
         sum[x] = val[x];
         size[x] = ;
         if (lc(x)) sum[x] += sum[lc(x)], size[x] += size[lc(x)];
         if (rc(x)) sum[x] += sum[rc(x)], size[x] += size[rc(x)];
         sum[x] %= mod;
     }

     void time(int x, ll d) {
         val[x] = val[x] * d % mod;
         sum[x] = sum[x] * d % mod;
         ad[x] = ad[x] * d % mod;
         tim[x] = tim[x] * d % mod;
     }

     void add(int x, ll d) {
         sum[x] = (sum[x] + d * size[x]) % mod;
         val[x] = (val[x] + d) % mod;
         ad[x] = (ad[x] + d) % mod;
     }

     void rev(int x) {
         swap(lc(x), rc(x));
         tun[x] ^= ;
     }

     void pushdown(int x) {
         if (tim[x] != ) {
             if (lc(x)) time(lc(x), tim[x]);
             if (rc(x)) time(rc(x), tim[x]);
             tim[x] = ;
         }
         if (ad[x]) {
             if (lc(x)) add(lc(x), ad[x]);
             if (rc(x)) add(rc(x), ad[x]);
             ad[x] = ;
         }
         if (tun[x]) {
             if (lc(x)) rev(lc(x));
             if (rc(x)) rev(rc(x));
             tun[x] = ;
         }
     }

     void pd(int x) {
         if (!isroot(x))
             pd(f[x]);
         pushdown(x);
     }

     void rotate(int x) {
         int old = f[x], oldf = f[old], son = ch[x][get(x) ^ ];
         if (!isroot(old)) ch[oldf][get(old)] = x;
         ch[x][get(x) ^ ] = old;
         ch[old][get(x)] = son;
         f[old] = x; f[x] = oldf; f[son] = old;
         up(old); up(x);
     }

     void splay(int x) {
         pd(x);
         for (; !isroot(x); rotate(x))
             if(!isroot(f[x]))
                 rotate(get(f[x]) == get(x) ? f[x] : x);
     }

     void access(int x) {
         for (int y = ; x; y = x, x = f[x])
             splay(x), ch[x][] = y, up(x);
     }

     void mroot(int x) {
         access(x); splay(x); rev(x);
     }

     void split(int x, int y) {
         mroot(x); access(y); splay(y);
     }

     void link(int x, int y) {
         mroot(x);
         f[x] = y;
     }

     void cut(int x, int y) {
         split(x, y);
         f[x] = ch[y][] = ;
         up(y);
     }
 }
 using namespace LCT;

 int main()
 {
     n = rd; m = rd;
     for (int i = ; i <= n; ++i)
         size[i] = tim[i] = val[i] = sum[i] = ;
     for (int i = ; i < n; ++i) {
         int u = rd, v = rd;
         link(u, v);
     }
     for (; m; m--) {
         char op[];
         scanf("%s", op);
         if (op[] == '+') {
             int u = rd, v = rd, d = rd;
             split(u, v);
             add(v, d);
         }
         if (op[] == '-') {
             int u = rd, v = rd;
             cut(u, v);
             u = rd; v = rd;
             link(u, v);
         }
         if (op[] == '*') {
             int u = rd, v = rd, d = rd;
             split(u, v);
             time(v, d);
         }
         if (op[] == '/') {
             int u = rd, v = rd;
             split(u, v);
             printf("%lld\n", sum[v] % mod);
         }
     }
 }