BZOJ1500 维修数列

  1 #include<bits/stdc++.h>
  2 using namespace std;
  3 template <class _T> inline void read(_T &_x) {
  4     int _t; bool flag = false;
  5     while ((_t = getchar()) != ‘-‘ && (_t < ‘0‘ || _t > ‘9‘)) ;
  6     if (_t == ‘-‘) _t = getchar(), flag = true; _x = _t - ‘0‘;
  7     while ((_t = getchar()) >= ‘0‘ && _t <= ‘9‘) _x = _x * 10 + _t - ‘0‘;
  8     if (flag) _x = -_x;
  9 }
 10 const int inf = 1010000000; //0x3f3f3f3f;
 11 const int maxn = 500010;
 12 int root, f[maxn], ch[maxn][2], sz[maxn], v[maxn], sum[maxn], lx[maxn], rx[maxn], mx[maxn];
 13 int st[maxn], top;
 14 bool rev[maxn], tag[maxn];
 15 inline int newnode() {
 16     int cur = st[--top];
 17     f[cur] = ch[cur][0] = ch[cur][1] = mx[cur] = 0;
 18     sz[cur] = 1, v[cur] = sum[cur] = lx[cur] = rx[cur] = -inf;
 19     rev[cur] = tag[cur] = false;
 20     return cur;
 21 }
 22 void print(int rt) {
 23     if (!rt) return ;
 24     print(ch[rt][0]);
 25     printf("%d ", v[rt]);
 26     print(ch[rt][1]);
 27 }
 28 void Print() {
 29     print(root);
 30     puts("");
 31 }
 32 inline void update(int c) {
 33     if (!c) return ;
 34     sz[c] = sz[ch[c][0]] + sz[ch[c][1]] + 1;
 35     sum[c] = sum[ch[c][0]] + sum[ch[c][1]] + v[c];
 36     lx[c] = max(lx[ch[c][0]], sum[ch[c][0]] + v[c] + max(0, lx[ch[c][1]]));
 37     rx[c] = max(rx[ch[c][1]], sum[ch[c][1]] + v[c] + max(0, rx[ch[c][0]]));
 38     mx[c] = max(max(mx[ch[c][0]], mx[ch[c][1]]), v[c] + max(rx[ch[c][0]], 0) + max(lx[ch[c][1]], 0));
 39 }
 40 inline void rotate(int c) {
 41     int b = f[c], a = f[b], x = ch[b][1]==c;
 42     ch[b][x] = ch[c][x ^ 1], f[ch[b][x]] = b;
 43     ch[c][x ^ 1] = b, f[b] = c;
 44     if (a) ch[a][ch[a][1]==b] = c; else root = c;
 45     f[c] = a; update(b);
 46 }
 47 inline void rever(int c) {
 48     if (!c) return ;
 49     swap(ch[c][0], ch[c][1]);
 50     swap(lx[c], rx[c]);
 51     rev[c] ^= 1;
 52 }
 53 inline void replace(int c, int val) {
 54     if (!c) return ;
 55     v[c] = val, sum[c] = sz[c] * val;
 56     lx[c] = rx[c] = mx[c] = max(val, val * sz[c]);
 57     tag[c] = 1, rev[c] = 0;
 58 }
 59 inline void pushdown(int c) {
 60     if (rev[c]) {
 61         if (ch[c][0]) rever(ch[c][0]);
 62         if (ch[c][1]) rever(ch[c][1]);
 63         rev[c] = 0;
 64     }
 65     if (tag[c]) {
 66         if (ch[c][0]) replace(ch[c][0], v[c]);
 67         if (ch[c][1]) replace(ch[c][1], v[c]);
 68         tag[c] = 0;
 69     }
 70 }
 71 inline void pushpath(int c) {
 72     if (f[c]) pushpath(f[c]);
 73     pushdown(c);
 74 }
 75 inline int splay(int c, int a = 0) {
 76     pushpath(c);
 77     for (int b; (b = f[c]) != a; rotate(c)) if (f[b] != a)
 78         rotate((ch[f[b]][0]==b)==(ch[b][0]==c)?b:c);
 79     update(c);
 80     return c;
 81 }
 82 inline int find_kth(int rt, int k) {
 83     int ori = f[rt];
 84     do {
 85         pushdown(rt);
 86         if (k == sz[ch[rt][0]] + 1) break;
 87         if (k <= sz[ch[rt][0]]) rt = ch[rt][0];
 88         else k -= sz[ch[rt][0]] + 1, rt = ch[rt][1];
 89     } while (true);
 90     return splay(rt, ori);
 91 }
 92 int a[maxn];
 93 void build(int &rt, int l, int r, int fa) {
 94     int mid = (l + r) >> 1;
 95     rt = newnode(), f[rt] = fa, v[rt] = a[mid];
 96     if (l < mid) build(ch[rt][0], l, mid - 1, rt);
 97     if (r > mid) build(ch[rt][1], mid + 1, r, rt);
 98     update(rt);
 99 }
100 inline int Query(int l, int len) {
101     int x = find_kth(root, l);
102     int y = find_kth(ch[x][1], len + 1);
103     return sum[ch[y][0]];
104 }
105 inline void Insert(int l, int len) {
106     for (int i = 1; i <= len; ++i) read(a[i]);
107     int x = find_kth(root, l + 1);
108     int y = find_kth(ch[x][1], 1);
109     build(ch[y][0], 1, len, y);
110     update(y), update(x);
111 }
112 void erase(int rt) {
113     if (!rt) return ;
114     st[top++] = rt;
115     erase(ch[rt][0]), erase(ch[rt][1]);
116 }
117 inline void Delete(int l, int len) {
118     int x = find_kth(root, l);
119     int y = find_kth(ch[x][1], len + 1);
120     erase(ch[y][0]), ch[y][0] = 0;
121     update(y), update(x);
122 }
123 inline void Reverse(int l, int len) {
124     int x = find_kth(root, l);
125     int y = find_kth(ch[x][1], len + 1);
126     rever(ch[y][0]);
127     update(y), update(x);
128 }
129 inline void Replace(int l, int len, int val) {
130     int x = find_kth(root, l);
131     int y = find_kth(ch[x][1], len + 1);
132     replace(ch[y][0], val);
133     update(y), update(x);
134 }
135 int n, m;
136 int main() {
137     //freopen("1500.txt", "r", stdin);
138     //freopen(".out", "w", stdout);
139     lx[0] = rx[0] = mx[0] = -inf;
140     read(n), read(m);
141     for (int i = 1; i < maxn; ++i) st[top++] = i;
142     int X = root = newnode();
143     int Y = ch[X][1] = newnode();
144     f[Y] = X;
145     for (int i = 1; i <= n; ++i) read(a[i]);
146     build(ch[Y][0], 1, n, Y);
147     update(Y), update(X);
148     char op[20];
149     while (m--) {
150         int x, y, z;
151         scanf("%s", op);
152         switch (op[0]) {
153             case ‘I‘:
154                 read(x), read(y);
155                 Insert(x, y);
156                 break;
157             case ‘D‘:
158                 read(x), read(y);
159                 Delete(x, y);
160                 break;
161             case ‘M‘:
162                 if (op[2] == ‘K‘) {
163                     read(x), read(y), read(z);
164                     Replace(x, y, z);
165                 } else {
166                     printf("%d\n", mx[root]);
167                 }
168                 break;
169             case ‘R‘:
170                 read(x), read(y);
171                 Reverse(x, y);
172                 break;
173             case ‘G‘:
174                 read(x), read(y);
175                 if (y == 0) puts("0");
176                 else printf("%d\n", Query(x, y));
177                 break;
178         }
179     }
180     return 0;
181 }