#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF = 1e18;
struct SegTree {
struct Node {
/* ans[l][r]:
* The maximum answer for this segment
*
* l and r are boolean variables denoting if we include the leftmost and rightmost elements
* respectively
*/
vector<vector<ll>> ans;
vector<ll> sign;
Node(void) {
ans.assign(2, vector<ll>(2, 0));
sign.assign(2, 0);
}
};
Node DEFAULT;
int size;
vector<Node> tree;
Node merge(const Node& a, const Node& b)
{
Node res;
res.sign[0] = a.sign[0];
res.sign[1] = b.sign[1];
if (a.sign[1] == b.sign[0] || a.sign[1] == 0 || b.sign[0] == 0) {
// We can merge
for (int l = 0; l < 2; l++) {
for (int r = 0; r < 2; r++) {
res.ans[l][r] = a.ans[l][1] + b.ans[1][r];
}
}
}
else {
for (int l = 0; l < 2; l++) {
for (int r = 0; r < 2; r++) {
res.ans[l][r] = max(a.ans[l][1] + b.ans[0][r], a.ans[l][0] + b.ans[1][r]);
}
}
}
return res;
}
int val(int v) {
if (v < 0) {
return -1;
}
if (v > 0) {
return 1;
}
return 0;
}
void init(int N) {
size = 1;
while (size < N) {
size *= 2;
}
tree.assign(2 * size, Node());
}
void build(vector<ll>& a, int x, int lx, int rx) {
if (lx == rx - 1) {
if (lx < a.size()) {
tree[x].ans[1][1] = abs(a[lx]);
tree[x].sign[0] = tree[x].sign[1] = val(a[lx]);
}
return;
}
int mid = (lx + rx) / 2;
build(a, 2 * x + 1, lx, mid);
build(a, 2 * x + 2, mid, rx);
tree[x] = merge(tree[2 * x + 1], tree[2 * x + 2]);
}
void build(vector<ll>& a) {
return build(a, 0, 0, size);
}
void set(int i, ll v, int x, int lx, int rx) {
if (lx == rx - 1) {
tree[x].ans[1][1] = abs(v);
tree[x].sign[0] = tree[x].sign[1] = val(v);
return;
}
int mid = (lx + rx) / 2;
if (i < mid) {
set(i, v, 2 * x + 1, lx, mid);
}
else {
set(i, v, 2 * x + 2, mid, rx);
}
tree[x] = merge(tree[2 * x + 1], tree[2 * x + 2]);
}
void set(int i, ll v) {
set(i, v, 0, 0, size);
}
ll calc(int l, int r) {
return tree[0].ans[1][1];
}
};
int N, Q;
SegTree st;
vector<int> A;
vector<ll> D;
int main(void)
{
scanf("%d %d", &N, &Q);
A.resize(N);
st.init(N - 1);
D.resize(N - 1);
for (int i = 0; i < N; i++) {
scanf("%d", &A[i]);
}
for (int i = 0; i < N - 1; i++) {
D[i] = A[i + 1] - A[i];
}
st.build(D);
while (Q--) {
int l, r, x;
scanf("%d %d %d", &l, &r, &x);
l--; l--;
r--;
if (l >= 0) {
D[l] += x;
st.set(l, D[l]);
}
if (r < N - 1) {
D[r] -= x;
st.set(r, D[r]);
}
printf("%lld\n", st.calc(0, N - 1));
}
return 0;
}
Compilation message
Main.cpp: In member function 'void SegTree::build(std::vector<long long int>&, int, int, int)':
Main.cpp:79:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
79 | if (lx < a.size()) {
| ~~~^~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:130:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
130 | scanf("%d %d", &N, &Q);
| ~~~~~^~~~~~~~~~~~~~~~~
Main.cpp:137:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
137 | scanf("%d", &A[i]);
| ~~~~~^~~~~~~~~~~~~
Main.cpp:146:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
146 | scanf("%d %d %d", &l, &r, &x);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
1 ms |
604 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
1 ms |
604 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
348 KB |
Output is correct |
7 |
Correct |
10 ms |
2140 KB |
Output is correct |
8 |
Correct |
10 ms |
2264 KB |
Output is correct |
9 |
Correct |
10 ms |
2140 KB |
Output is correct |
10 |
Correct |
10 ms |
2140 KB |
Output is correct |
11 |
Correct |
10 ms |
2140 KB |
Output is correct |
12 |
Correct |
10 ms |
2240 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
1 ms |
604 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
348 KB |
Output is correct |
7 |
Correct |
10 ms |
2140 KB |
Output is correct |
8 |
Correct |
10 ms |
2264 KB |
Output is correct |
9 |
Correct |
10 ms |
2140 KB |
Output is correct |
10 |
Correct |
10 ms |
2140 KB |
Output is correct |
11 |
Correct |
10 ms |
2140 KB |
Output is correct |
12 |
Correct |
10 ms |
2240 KB |
Output is correct |
13 |
Correct |
1366 ms |
115800 KB |
Output is correct |
14 |
Correct |
1389 ms |
118604 KB |
Output is correct |
15 |
Correct |
1337 ms |
118556 KB |
Output is correct |
16 |
Correct |
1343 ms |
118432 KB |
Output is correct |
17 |
Correct |
1319 ms |
118352 KB |
Output is correct |
18 |
Correct |
1337 ms |
119016 KB |
Output is correct |