因为swap写错而调试一下午的SPOJ GSS7

OnlineJudges/spoj/GSS7.cpp

@@ -0,0 +1,139 @@
+#include <cstdio>
+template <typename T>
+inline T max(const T &x, const T &y) { return x > y ? x : y; }
+template <typename T>
+inline void swap(T &x, T &y)
+{
+    T t = x;
+    x = y;
+    y = t;
+}
+struct node
+{
+    int val, lx, rx, mx, sum, sz;
+    node *ch[2], *fa;
+    bool rev, tag;
+    int dir() { return this == 0 || this->fa == 0 ? -1 : this == this->fa->ch[1]; }
+    bool isRoot() { return this->fa == 0 || (this != this->fa->ch[0] && this != this->fa->ch[1]); }
+#define _get(x, v) \
+    int get##x() { return this == 0 ? 0 : max(v, this->x); }
+    _get(lx, 0) _get(rx, 0) _get(mx, 0) _get(sum, -0x3f3f3f3f) _get(sz, 0)
+};
+inline void update(node *x)
+{
+    if (x == 0) return;
+    node *lc = x->ch[0], *rc = x->ch[1];
+    x->sz = lc->getsz() + 1 + rc->getsz();
+    x->sum = x->val + lc->getsum() + rc->getsum();
+    x->mx = max(x->val, max(lc->getmx(), rc->getmx()));
+    x->mx = max(x->mx, lc->getrx() + x->val + rc->getlx());
+    x->lx = max(lc->getlx(), lc->getsum() + x->val + rc->getlx());
+    x->rx = max(rc->getrx(), rc->getsum() + x->val + lc->getrx());
+}
+inline void rev_tree(node *x)
+{
+    if (x == 0) return;
+    swap(x->lx, x->rx);
+    swap(x->ch[0], x->ch[1]);
+    x->rev ^= 1;
+}
+inline void set_tree(node *x, int v)
+{
+    if (x == 0) return;
+    x->sum = x->sz * (x->val = v);
+    x->lx = x->rx = x->mx = max(0, x->sum);
+    x->tag = true;
+}
+inline void push_down(node *x)
+{
+    if (x == 0) return;
+    if (x->rev)
+    {
+        if (x->ch[0]) rev_tree(x->ch[0]);
+        if (x->ch[1]) rev_tree(x->ch[1]);
+        x->rev = false;
+    }
+    if (x->tag)
+    {
+        if (x->ch[0]) set_tree(x->ch[0], x->val);
+        if (x->ch[1]) set_tree(x->ch[1], x->val);
+        x->tag = false;
+    }
+}
+void push_down_rec(node *x)
+{
+    if (!x->isRoot()) push_down_rec(x->fa);
+    push_down(x);
+}
+inline void liftup(node *x)
+{
+    if (x == 0 || x->isRoot()) return;
+    int d = x->dir();
+    node *f = x->fa, *ff = f->fa, *c = x->ch[d ^ 1];
+    if (!f->isRoot()) ff->ch[f->dir()] = x;
+    f->fa = x, x->fa = ff, x->ch[d ^ 1] = f, f->ch[d] = c;
+    if (c) c->fa = f;
+    update(f), update(x);
+}
+inline void splay(node *x)
+{
+    push_down_rec(x);
+    for (; !x->isRoot(); liftup(x))
+        if (!x->fa->isRoot())
+            liftup(x->dir() ^ x->fa->dir() ? x : x->fa);
+    update(x);
+}
+inline node *access(node *x)
+{
+    node *y = 0;
+    for (; x; y = x, x = x->fa)
+    {
+        splay(x), x->ch[1] = y;
+        if (y) y->fa = x;
+    }
+    return y;
+}
+inline node *findRoot(node *x)
+{
+    access(x), splay(x);
+    while (push_down(x), x->ch[0]) x = x->ch[0];
+    return splay(x), x;
+}
+inline void makeRoot(node *x)
+{
+    access(x), splay(x), rev_tree(x);
+}
+inline void Link(node *x, node *f)
+{
+    makeRoot(x), x->fa = f;
+}
+inline void Cut(node *x, node *y)
+{
+    makeRoot(x), access(y), splay(y);
+    x->fa = y->ch[0] = 0;
+}
+inline node *Select(node *x, node *y)
+{
+    return makeRoot(x), findRoot(y);
+}
+int main()
+{
+    static node T[100010];
+    int n, q;
+    scanf("%d", &n);
+    for (int i = 1; i <= n; i++) scanf("%d", &T[i].val), update(&T[i]);
+    for (int i = 1, u, v; i < n; i++)
+        scanf("%d%d", &u, &v), Link(&T[u], &T[v]);
+    scanf("%d", &q);
+    while (q--)
+    {
+        int op, a, b, c;
+        scanf("%d%d%d", &op, &a, &b);
+        node *target = Select(&T[a], &T[b]);
+        if (op == 1)
+            printf("%d\n", target->getmx());
+        if (op == 2)
+            scanf("%d", &c), set_tree(target, c);
+    }
+    return 0;
+}