SPOJ 4487 Can you answer these queries VI

SPOJ_4487

    其实这个题目和GSS1是差不多的，只不过由于有增加和删除的操作，这样用线段树就搞不定了，因此可以维护一个splay来实现这些操作。

    但是一开始我写出的程序总是TLE，而和网上一些AC的程序对照之后发现无非有两点很不同的地方，一个是他们都用了结构体，另一个是他们都用了指针。在百思不得其解之际，我把以前的若干个数组仿照一个AC的程序写成了结构体，就像下面这样：

struct Splay
{
    int left, right, pre, size, sum, mc, key, lc, rc;
    #define left(x) sp[x].left
    #define right(x) sp[x].right
    #define pre(x) sp[x].pre
    #define size(x) sp[x].size
    #define sum(x) sp[x].sum
    #define mc(x) sp[x].mc
    #define key(x) sp[x].key
    #define lc(x) sp[x].lc
    #define rc(x) sp[x].rc
}sp[MAXD];

    尼玛……居然AC了……

    不知道这是不是也算底层优化……各位TLE了的同仁不妨试试写成结构体……

#include<stdio.h>
#include<string.h>
#include<cstdlib>
#define MAXD 200010
#define INF 0x3f3f3f3f
int N, T, a[MAXD], node;
struct Splay
{
    int left, right, pre, size, sum, mc, key, lc, rc;
    #define left(x) sp[x].left
    #define right(x) sp[x].right
    #define pre(x) sp[x].pre
    #define size(x) sp[x].size
    #define sum(x) sp[x].sum
    #define mc(x) sp[x].mc
    #define key(x) sp[x].key
    #define lc(x) sp[x].lc
    #define rc(x) sp[x].rc
}sp[MAXD];
int Max(int x, int y)
{
    return x > y ? x : y;
}
void newnode(int &cur, int v)
{
    cur = ++ node;
    size(cur) = 1;
    key(cur) = sum(cur) = mc(cur) = lc(cur) = rc(cur) = v;
    left(cur) = right(cur) = 0;
}
void update(int cur)
{
    int ls = left(cur), rs = right(cur);
    size(cur) = size(ls) + size(rs) + 1;
    sum(cur) = sum(ls) + sum(rs) + key(cur);
    mc(cur) = Max(rc(ls), 0) + key(cur) + Max(lc(rs), 0);
    mc(cur) = Max(mc(cur), Max(mc(ls), mc(rs)));
    lc(cur) = Max(lc(ls), sum(ls) + key(cur) + Max(lc(rs), 0));
    rc(cur) = Max(rc(rs), sum(rs) + key(cur) + Max(rc(ls), 0));
}
void leftrotate(int cur)
{
    int k = right(cur), fa = pre(cur);
    right(cur) = left(k);
    pre(right(cur)) = cur;
    left(k) = cur;
    pre(cur) = k;
    pre(k) = fa;
    right(fa) == cur ? right(fa) = k : left(fa) = k;
    update(cur);
}
void rightrotate(int cur)
{
    int k = left(cur), fa = pre(cur);
    left(cur) = right(k);
    pre(left(cur)) = cur;
    right(k) = cur;
    pre(cur) = k;
    pre(k) = fa;
    right(fa) == cur ? right(fa) = k : left(fa) = k;
    update(cur);
}
void build(int &cur, int x, int y, int fa)
{
    int mid = (x + y) >> 1;
    newnode(cur, a[mid]);
    pre(cur) = fa;
    if(x == y)
        return ;
    if(x < mid)
        build(left(cur), x, mid - 1, cur);
    if(mid < y)
        build(right(cur), mid + 1, y, cur);
    update(cur);
}
void splay(int x, int goal)
{
    int y, z;
    for(;;)
    {
        if((y = pre(x)) == goal)
            break;
        if((z = pre(y)) == goal)
            right(y) == x ? leftrotate(y) : rightrotate(y);
        else
        {
            if(right(z) == y)
                right(y) == x ? (leftrotate(z), leftrotate(y)) : (rightrotate(y), leftrotate(z));
            else
                left(y) == x ? (rightrotate(z), rightrotate(y)) : (leftrotate(y), rightrotate(z));
        }
    }
    if(goal == 0)
        T = x;
    update(x);
}
void rotateto(int k, int goal)
{
    int cur = T, n;
    for(;;)
    {
        n = size(left(cur)) + 1;
        if(n == k)
            break;
        if(k < n)
            cur = left(cur);
        else
            k -= n, cur = right(cur);
    }
    splay(cur, goal);
}
void init()
{
    int i;
    for(i = 1; i <= N; i ++)
        scanf("%d", &a[i]);
    node = size(0) = sum(0) = 0;
    mc(0) = lc(0) = rc(0) = -INF;
    newnode(T, 0), newnode(right(T), 0);
    pre(right(T)) = T;
    key(T) = key(right(T)) = 0;
    if(N)
        build(left(right(T)), 1, N, right(T));
    update(right(T)), update(T);
}
void Delete(int x)
{
    rotateto(x, 0), rotateto(x + 2, T);
    left(right(T)) = 0;
    update(right(T)), update(T);
}
void Insert(int x, int y)
{
    rotateto(x, 0), rotateto(x + 1, T);
    newnode(left(right(T)), y);
    pre(node) = right(T);
    update(right(T)), update(T);
}
void Replace(int x, int y)
{
    rotateto(x + 1, 0);
    key(T) = y;
    update(T);
}
void Query(int x, int y)
{
    rotateto(x, 0), rotateto(y + 2, T);
    printf("%d\n", mc(left(right(T))));
}
void solve()
{
    int i, q, x, y;
    char op[5];
    scanf("%d", &q);
    for(i = 0; i < q; i ++)
    {
        scanf("%s", op);
        if(op[0] == 'D')
        {
            scanf("%d", &x);
            Delete(x);
        }
        else
        {
            scanf("%d%d", &x, &y);
            if(op[0] == 'I')
                Insert(x, y);
            else if(op[0] == 'R')
                Replace(x, y);
            else
                Query(x, y);
        }
    }
}
int main()
{
    while(scanf("%d", &N) == 1)
    {
        init();
        solve();
    }
    return 0;
}