# [BZOJ 3531] [Sdoi2014] 旅行 【离线+LCT】

### 代码

#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <queue>

using namespace std;

inline void Read(int &Num)
{
char c = getchar();
bool Neg = false;
while (c < '0' || c > '9')
{
if (c == '-') Neg = true;
c = getchar();
}
Num = c - '0'; c = getchar();
while (c >= '0' && c <= '9')
{
Num = Num * 10 + c - '0';
c = getchar();
}
if (Neg) Num = -Num;
}

inline int gmin(int a, int b) {return a < b ? a : b;}
inline int gmax(int a, int b) {return a > b ? a : b;}

const int MaxN = 100000 + 5, MaxM = 100000 + 5, INF = 999999999;

int n, m, QTop, ATot;
int W[MaxN], C[MaxN], WT[MaxN], CT[MaxN], Ans[MaxM], Father[MaxN], T[MaxN], Sum[MaxN], Max[MaxN], Son[MaxN][2];

bool isRoot[MaxN], Rev[MaxN];

struct Edge
{
int v;
Edge *Next;
} E[MaxN * 2], *P = E, *Point[MaxN];

inline void AddEdge(int x, int y)
{
++P; P -> v = y;
P -> Next = Point[x]; Point[x] = P;
}

struct ES
{
int Type, Col, Pos, Num, x, y, TL, AIdx;
/*
TypeList:
1 : Change City-Pos to Num
2 : Qsum of the path(x, y)
3 : Qmax of the path(x, y)
*/
} Q[MaxN * 2 + MaxM * 2];

inline bool Cmp(ES e1, ES e2)
{
if (e1.Col != e2.Col) return e1.Col < e2.Col;
return e1.TL < e2.TL;
}

queue<int> Qe;

void BFS()
{
while (!Qe.empty()) Qe.pop();
Qe.push(1); Father[1] = 0;
int x;
while (!Qe.empty())
{
x = Qe.front(); Qe.pop();
for (Edge *j = Point[x]; j; j = j -> Next)
{
if (j -> v == Father[x]) continue;
Father[j -> v] = x;
Qe.push(j -> v);
}
}
}

/************************ LCT Start ****************************/

inline void Update(int x)
{
Sum[x] = Sum[Son[x][0]] + Sum[Son[x][1]] + T[x];
Max[x] = gmax(T[x], gmax(Max[Son[x][0]], Max[Son[x][1]]));
}

inline void Reverse(int x)
{
Rev[x] = !Rev[x];
swap(Son[x][0], Son[x][1]);
}

inline void PushDown(int x)
{
if (!Rev[x]) return;
Rev[x] = false;
if (Son[x][0]) Reverse(Son[x][0]);
if (Son[x][1]) Reverse(Son[x][1]);
}

inline int GetDir(int x) {return x == Son[Father[x]][0] ? 0 : 1;}

void Rotate(int x)
{
int y = Father[x], f = GetDir(x) ^ 1;
PushDown(y); PushDown(x);
if (isRoot[y])
{
isRoot[y] = false;
isRoot[x] = true;
}
else Son[Father[y]][GetDir(y)] = x;
Father[x] = Father[y];
Son[y][f ^ 1] = Son[x][f];
if (Son[x][f]) Father[Son[x][f]] = y;
Son[x][f] = y; Father[y] = x;
Update(y); Update(x);
}

void Splay(int x)
{
int y;
while (!isRoot[x])
{
y = Father[x];
if (isRoot[y])
{
Rotate(x);
break;
}
if (GetDir(x) == GetDir(y)) Rotate(y);
else Rotate(x);
Rotate(x);
}
}

inline int Access(int x)
{
int y = 0;
while (x != 0)
{
Splay(x);
PushDown(x);
if (Son[x][1]) isRoot[Son[x][1]] = true;
Son[x][1] = y;
if (y) isRoot[y] = false;
Update(x);
y = x;
x = Father[x];
}
return y;
}

inline void Make_Root(int x)
{
int t = Access(x);
Reverse(t);
}

/************************ LCT End ****************************/

int main()
{
scanf("%d%d", &n, &m);
for (int i = 1; i <= n; ++i)
{
Read(W[i]); Read(C[i]);
WT[i] = W[i]; CT[i] = C[i];
}
int a, b;
for (int i = 1; i <= n - 1; ++i)
{
Read(a); Read(b);
AddEdge(a, b); AddEdge(b, a);
}
char Str[5];
for (int i = 1; i <= n; ++i)
{
++QTop; Q[QTop].TL = 0; Q[QTop].Col = CT[i];
Q[QTop].Type = 1; Q[QTop].Pos = i; Q[QTop].Num = WT[i];
}
for (int i = 1; i <= m; ++i)
{
scanf("%s", Str);
Read(a); Read(b);
if (strcmp(Str, "CC") == 0)
{
++QTop; Q[QTop].TL = i; Q[QTop].Col = CT[a];
Q[QTop].Type = 1; Q[QTop].Pos = a; Q[QTop].Num = 0;
++QTop; Q[QTop].TL = i; Q[QTop].Col = b;
Q[QTop].Type = 1; Q[QTop].Pos = a; Q[QTop].Num = WT[a];
CT[a] = b;
}
else if (strcmp(Str, "CW") == 0)
{
++QTop; Q[QTop].TL = i; Q[QTop].Col = CT[a];
Q[QTop].Type = 1; Q[QTop].Pos = a; Q[QTop].Num = b;
WT[a] = b;
}
else if (strcmp(Str, "QS") == 0)
{
++QTop; Q[QTop].TL = i; Q[QTop].Col = CT[a];
Q[QTop].Type = 2; Q[QTop].x = a; Q[QTop].y = b; Q[QTop].AIdx = ++ATot;
}
else if (strcmp(Str, "QM") == 0)
{
++QTop; Q[QTop].TL = i; Q[QTop].Col = CT[a];
Q[QTop].Type = 3; Q[QTop].x = a; Q[QTop].y = b; Q[QTop].AIdx = ++ATot;
}
}
for (int i = 1; i <= n; ++i)
{
++QTop; Q[QTop].TL = INF; Q[QTop].Col = CT[i];
Q[QTop].Type = 1; Q[QTop].Pos = i; Q[QTop].Num = 0;
}
sort(Q + 1, Q + QTop + 1, Cmp);
BFS();
for (int i = 1; i <= n; ++i)
{
isRoot[i] = true; Rev[i] = false;
T[i] = 0; Max[i] = 0; Sum[i] = 0;
}
int t;
for (int i = 1; i <= QTop; ++i)
{
if (Q[i].Type == 1)
{
Splay(Q[i].Pos);
T[Q[i].Pos] = Q[i].Num;
Update(Q[i].Pos);
}
else
{
Make_Root(Q[i].x);
t = Access(Q[i].y);
if (Q[i].Type == 2) Ans[Q[i].AIdx] = Sum[t];
else Ans[Q[i].AIdx] = Max[t];
}
}
for (int i = 1; i <= ATot; ++i) printf("%d\n", Ans[i]);
return 0;
}


posted @ 2015-04-25 21:27  JoeFan  阅读(268)  评论(0编辑  收藏  举报