# CodeForces - 280D k-Maximum Subsequence Sum

### Decription

$n,q\le 10^5,k\le 20$

### Solution

#include<bits/stdc++.h>
using namespace std;

template <class T> void read(T &x) {
x = 0; bool flag = 0; char ch = getchar(); for (; ch < '0' || ch > '9'; ch = getchar()) flag |= ch == '-';
for (; ch >= '0' && ch <= '9'; ch = getchar()) x = x * 10 + ch - 48; flag ? x = ~x + 1 : 0;
}

//#pragma GCC diagnostic error "-std=c++14"

#define N 100010
#define rep(i, a, b) for (auto i = (a); i <= (b); ++i)
#define drp(i, a, b) for (auto i = (a); i >= (b); --i)
#define ll long long
#define INF 0x3f3f3f3f

struct Data {
int sum, lval, rval, sval, sl, sr, lr, rl;
Data(int _sum = 0, int _lval = 0, int _rval = 0, int _sval = 0, int _sl = 0, int _sr = 0, int _lr = 0, int _rl = 0) {
sum = _sum, lval = _lval, rval = _rval, sval = _sval, sl = _sl, sr = _sr, lr = _lr, rl = _rl;
}
void reverse() {
sum *= -1, lval *= -1, rval *= -1, sval *= -1;
}
void init(int t) {
lval = rval = sval = INF;
if (t) reverse();
}
void merge(const Data& l, const Data& r, bool t) {
sum = l.sum + r.sum;
if (t) {
lval = max(l.lval, l.sum + r.lval), rval = max(r.rval, r.sum + l.rval);
sval = max(max(l.sval, r.sval), l.rval + r.lval);
}
else {
lval = min(l.lval, l.sum + r.lval), rval = min(r.rval, r.sum + l.rval);
sval = min(min(l.sval, r.sval), l.rval + r.lval);
}
lr = (lval == l.lval ? l.lr : r.lr);
rl = (rval == r.rval ? r.rl : l.rl);
if (sval == l.sval) sl = l.sl, sr = l.sr;
else if (sval == r.sval) sl = r.sl, sr = r.sr;
else sl = l.rl, sr = r.lr;
}
};

struct Node {
Data mx, mn;
void init() {
mx.init(1), mn.init(0);
}
}T[N << 2];

int n, a[N];
bool tag[N << 2];

#define ls rt << 1
#define rs ls | 1
#define mid (l + r >> 1)

void pushup(Node& now, const Node& l, const Node& r) {
now.init();
now.mx.merge(l.mx, r.mx, 1), now.mn.merge(l.mn, r.mn, 0);
}

void pushDown(int rt) {
if (tag[rt]) {
T[ls].mx.reverse(), T[rs].mx.reverse();
T[ls].mn.reverse(), T[rs].mn.reverse();
swap(T[ls].mx, T[ls].mn), swap(T[rs].mx, T[rs].mn);
tag[ls] ^= 1, tag[rs] ^= 1, tag[rt] = 0;
}
}

void update(int rt, int l, int r, int p) {
if (l == r) {
T[rt].mn = T[rt].mx = Data(a[l], a[l], a[l], a[l], l, r, l, r);
return;
}
pushDown(rt);
p <= mid ? update(ls, l, mid, p) : update(rs, mid + 1, r, p);
pushup(T[rt], T[ls], T[rs]);
}

Node query(int rt, int l, int r, int L, int R) {
if (L <= l && r <= R) return T[rt];
pushDown(rt);
Node ret, lret, rret;
ret.init(), lret.init(), rret.init();
if (L <= mid) lret = query(ls, l, mid, L, R);
if (R > mid) rret = query(rs, mid + 1, r, L, R);
if (R <= mid) ret = lret;
else if (L > mid) ret = rret;
else pushup(ret, lret, rret);
return ret;
}

void update(int rt, int l, int r, int L, int R) {
if (L <= l && r <= R) {
T[rt].mx.reverse(), T[rt].mn.reverse();
swap(T[rt].mx, T[rt].mn);
tag[rt] ^= 1;
return;
}
pushDown(rt);
if (L <= mid) update(ls, l, mid, L, R);
if (R > mid) update(rs, mid + 1, r, L, R);
pushup(T[rt], T[ls], T[rs]);
}

int ans = 0;
void dfs(int k, int l, int r) {
Node ret = query(1, 1, n, l, r);
if (ret.mx.sval <= 0) return;
ans += ret.mx.sval;
update(1, 1, n, ret.mx.sl, ret.mx.sr);
if (k - 1) dfs(k - 1, l, r);
update(1, 1, n, ret.mx.sl, ret.mx.sr);
}

int main() {
rep(i, 1, n) read(a[i]), update(1, 1, n, i);
while (q--) {
if (!op) {
}