【BZOJ1500】[NOI2005]维修数列【Splay】
http://www.lydsy.com/JudgeOnline/problem.php?id=1500
这神题终于过了...
主要是：
find()那里少写了一个pushdown()。
辣鸡回收写跪了。
似乎不用pushdown(root)...
/* Footprints In The Blood Soaked Snow */
#include
#include
using namespace std;
const int maxn = 500005, inf = 0x3f3f3f3f;
int n, m, num[maxn];
int son[maxn][2], pre[maxn], size[maxn], lx[maxn], rx[maxn], sum[maxn], mx[maxn], val[maxn];
int root, tot1, tot2, sta[maxn];
bool rev[maxn], same[maxn];
inline void newnode(int &x, int c, int f) {
x = tot2 ? sta[tot2--] : ++tot1;
son[x][0] = son[x][1] = 0;
pre[x] = f;
size[x] = 1;
sum[x] = mx[x] = lx[x] = rx[x] = val[x] = c;
rev[x] = same[x] = 0;
}
inline void pushup(int x) {
int l = son[x][0], r = son[x][1];
size[x] = size[l] + size[r] + 1;
sum[x] = sum[l] + val[x] + sum[r];
mx[x] = max(max(mx[l], mx[r]), max(0, rx[l]) + val[x] + max(0, lx[r]));
lx[x] = max(lx[l], sum[l] + val[x] + max(0, lx[r]));
rx[x] = max(rx[r], max(0, rx[l]) + val[x] + sum[r]);
}
inline void pushdown(int x) {
int l = son[x][0], r = son[x][1];
if(rev[x]) {
rev[l] ^= 1; rev[r] ^= 1;
swap(son[l][0], son[l][1]); swap(son[r][0], son[r][1]);
swap(lx[l], rx[l]); swap(lx[r], rx[r]);
rev[x] = 0;
}
if(same[x]) {
if(l) same[l] = 1, val[l] = val[x], sum[l] = val[l] * size[l], lx[l] = rx[l] = mx[l] = max(val[l], sum[l]);
if(r) same[r] = 1, val[r] = val[x], sum[r] = val[r] * size[r], lx[r] = rx[r] = mx[r] = max(val[r], sum[r]);
same[x] = 0;
}
}
inline void build(int &x, int l, int r, int f) {
if(l > r) return;
int mid = l + r >> 1;
newnode(x, num[mid], f);
build(son[x][0], l, mid - 1, x); build(son[x][1], mid + 1, r, x);
pushup(x);
}
inline void init() {
tot1 = tot2 = root = 0;
son[0][0] = son[0][1] = pre[0] = size[0] = rev[0] = same[0] = sum[0] = val[0] = 0;
lx[0] = rx[0] = mx[0] = -inf;
newnode(root, -inf, 0);
newnode(son[root][1], -inf, root);
build(son[son[root][1]][0], 1, n, son[root][1]);
pushup(son[root][1]); pushup(root);
}
inline void rotate(int x) {
int y = pre[x], z = pre[y], type = son[y][1] == x;
pre[son[y][type] = son[x][!type]] = y;
pre[x] = z;
if(z) son[z][son[z][1] == y] = x;
pre[son[x][!type] = y] = x;
pushup(y); pushup(x);
}
inline void splay(int x, int goal) {
while(pre[x] != goal) {
int y = pre[x], z = pre[y];
if(z == goal) rotate(x);
else if(son[z][0] == y ^ son[y][0] == x) rotate(x), rotate(x);
else rotate(y), rotate(x);
}
if(goal == 0) root = x;
}
inline int find(int k) {
int x = root;
for(pushdown(x); k != size[son[x][0]] + 1; pushdown(x))
if(k <= size[son[x][0]]) x = son[x][0];
else k -= size[son[x][0]] + 1, x = son[x][1];
return x;
}
inline void insert(int pos, int tot) {
int x = find(pos + 1), y = find(pos + 2);
splay(x, 0); splay(y, root);
build(son[y][0], 1, tot, y);
pushup(y); pushup(x);
}
inline void erase(int x) {
if(!x) return;
sta[++tot2] = x;
erase(son[x][0]); erase(son[x][1]);
son[x][0] = son[x][1] = pre[x] = rev[x] = same[x] = size[x] = 0;
}
inline void del(int pos, int tot) {
int x = find(pos), y = find(pos + tot + 1);
splay(x, 0); splay(y, root);
erase(son[y][0]);
son[y][0] = 0;
pushup(son[root][1]); pushup(root);
}
inline void makesame(int pos, int tot, int c) {
int x = find(pos), y = find(pos + tot + 1);
splay(x, 0); splay(y, root);
int u = son[y][0];
same[u] = 1;
val[u] = c;
sum[u] = val[u] * size[u];
lx[u] = rx[u] = mx[u] = max(val[u], sum[u]);
pushup(son[root][1]); pushup(root);
}
inline void reverse(int pos, int tot) {
int x = find(pos), y = find(pos + tot + 1);
splay(x, 0); splay(y, root);
int u = son[y][0];
if(same[u]) return;
rev[u] ^= 1;
swap(son[u][0], son[u][1]);
swap(lx[u], rx[u]);
pushup(son[root][1]); pushup(root);
}
inline int getsum(int pos, int tot) {
int x = find(pos), y = find(pos + tot + 1);
splay(x, 0); splay(y, root);
return sum[son[y][0]];
}
char opt[25];
int main() {
scanf("%d%d", &n, &m);
for(int i = 1; i <= n; i++) scanf("%d", &num[i]);
init();
int cnt = 1;
while(m--) {
scanf("%s", opt);
if(opt[0] == 'I') {
int pos, tot; scanf("%d%d", &pos, &tot);
for(int i = 1; i <= tot; i++) scanf("%d", &num[i]);
insert(pos, tot);
}
else if(opt[0] == 'D') {
int pos, tot; scanf("%d%d", &pos, &tot);
del(pos, tot);
}
else if(opt[0] == 'M' && opt[2] == 'K') {
int pos, tot, c; scanf("%d%d%d", &pos, &tot, &c);
makesame(pos, tot, c);
}
else if(opt[0] == 'R') {
int pos, tot; scanf("%d%d", &pos, &tot);
reverse(pos, tot);
}
else if(opt[0] == 'G') {
int pos, tot; scanf("%d%d", &pos, &tot);
printf("%d\n", getsum(pos, tot));
}
else if(opt[0] == 'M' && opt[2] == 'X')
printf("%d\n", mx[root]);
}
return 0;
}
再写一遍。
/* Footprints In The Blood Soaked Snow */
#include
#include
using namespace std;
const int maxn = 500005, inf = 0x3f3f3f3f;
int n, m, num[maxn];
int son[maxn][2], size[maxn], pre[maxn], lx[maxn], rx[maxn], mx[maxn], sum[maxn], val[maxn];
int root, tot1, tot2, sta[maxn];
bool rev[maxn], same[maxn];
inline int iread() {
int f = 1, x = 0; char ch = getchar();
for(; ch < '0' || ch > '9'; ch = getchar()) f = ch == '-' ? -1 : 1;
for(; ch >= '0' && ch <= '9'; ch = getchar()) x = x * 10 + ch - '0';
return f * x;
}
inline void newnode(int &x, int c, int f) {
x = tot2 ? sta[tot2--] : ++tot1;
son[x][0] = son[x][1] = 0;
pre[x] = f;
size[x] = 1;
lx[x] = rx[x] = mx[x] = sum[x] = val[x] = c;
rev[x] = same[x] = 0;
}
inline void pushup(int x) {
int l = son[x][0], r = son[x][1];
size[x] = size[l] + size[r] + 1;
sum[x] = sum[l] + val[x] + sum[r];
mx[x] = max(max(mx[l], mx[r]), max(0, rx[l]) + val[x] + max(0, lx[r]));
lx[x] = max(lx[l], sum[l] + val[x] + max(0, lx[r]));
rx[x] = max(rx[r], max(0, rx[l]) + val[x] + sum[r]);
}
inline void pushdown(int x) {
int l = son[x][0], r = son[x][1];
if(rev[x]) {
rev[l] ^= 1; rev[r] ^= 1;
swap(son[l][0], son[l][1]); swap(son[r][0], son[r][1]);
swap(lx[l], rx[l]); swap(lx[r], rx[r]);
rev[x] = 0;
}
if(same[x]) {
if(l) same[l] = 1, val[l] = val[x], sum[l] = val[l] * size[l], lx[l] = rx[l] = mx[l] = max(val[l], sum[l]);
if(r) same[r] = 1, val[r] = val[x], sum[r] = val[r] * size[r], lx[r] = rx[r] = mx[r] = max(val[r], sum[r]);
same[x] = 0;
}
}
inline void build(int &x, int l, int r, int f) {
if(l > r) return;
int mid = l + r >> 1;
newnode(x, num[mid], f);
build(son[x][0], l, mid - 1, x); build(son[x][1], mid + 1, r, x);
pushup(x);
}
inline void init() {
tot1 = tot2 = root = 0;
son[0][0] = son[0][1] = size[0] = pre[0] = sum[0] = val[0] = 0;
lx[0] = rx[0] = mx[0] = -inf;
newnode(root, -inf, 0);
newnode(son[root][1], -inf, root);
build(son[son[root][1]][0], 1, n, son[root][1]);
pushup(son[root][1]); pushup(root);
}
inline void rotate(int x) {
int y = pre[x], z = pre[y], type = son[y][1] == x;
pre[son[y][type] = son[x][!type]] = y;
pre[x] = z;
if(z) son[z][son[z][1] == y] = x;
pre[son[x][!type] = y] = x;
pushup(y); pushup(x);
}
inline void splay(int x, int goal) {
while(pre[x] ^ goal) {
int y = pre[x], z = pre[y];
if(z == goal) rotate(x);
else if(son[z][1] == y ^ son[y][1] == x) rotate(x), rotate(x);
else rotate(y), rotate(x);
}
if(goal == 0) root = x;
}
inline int find(int k) {
int x = root;
for(; k != size[son[x][0]] + 1; pushdown(x))
if(k <= size[son[x][0]]) x = son[x][0];
else k -= size[son[x][0]] + 1, x = son[x][1];
return x;
}
inline void insert(int pos, int tot) {
int x = find(pos + 1), y = find(pos + 2);
splay(x, 0); splay(y, root);
build(son[y][0], 1, tot, y);
pushup(y); pushup(x);
}
inline void erase(int x) {
if(!x) return;
sta[++tot2] = x;
erase(son[x][0]); erase(son[x][1]);
son[x][0] = son[x][1] = pre[x] = size[x] = rev[x] = same[x] = 0;
}
inline void del(int pos, int tot) {
int x = find(pos), y = find(pos + tot + 1);
splay(x, 0); splay(y, root);
erase(son[y][0]);
son[y][0] = 0;
pushup(y); pushup(x);
}
inline void makesame(int pos, int tot, int c) {
int x = find(pos), y = find(pos + tot + 1);
splay(x, 0); splay(y, root);
int u = son[y][0];
same[u] = 1;
val[u] = c;
sum[u] = val[u] * size[u];
lx[u] = rx[u] = mx[u] = max(val[u], sum[u]);
pushup(y); pushup(x);
}
inline void reverse(int pos, int tot) {
int x = find(pos), y = find(pos + tot + 1);
splay(x, 0); splay(y, root);
int u = son[y][0];
if(same[u]) return;
rev[u] ^= 1;
swap(son[u][0], son[u][1]);
swap(lx[u], rx[u]);
pushup(y); pushup(x);
}
inline int getsum(int pos, int tot) {
int x = find(pos), y = find(pos + tot + 1);
splay(x, 0); splay(y, root);
return sum[son[y][0]];
}
char str[25];
int main() {
n = iread(); m = iread();
for(int i = 1; i <= n; i++) num[i] = iread();
init();
while(m--) {
scanf("%s", str);
if(str[2] == 'S') {
int pos = iread(), tot = iread();
for(int i = 1; i <= tot; i++) num[i] = iread();
insert(pos, tot);
}
else if(str[2] == 'L') {
int pos = iread(), tot = iread();
del(pos, tot);
}
else if(str[2] == 'K') {
int pos = iread(), tot = iread(), c = iread();
makesame(pos, tot, c);
}
else if(str[2] == 'V') {
int pos = iread(), tot = iread();
reverse(pos, tot);
}
else if(str[2] == 'T') {
int pos = iread(), tot = iread();
printf("%d\n", getsum(pos, tot));
}
else if(str[2] == 'X')
printf("%d\n", mx[root]);
}
return 0;
}