/**
* author: wxhtzdy
* created: 02.07.2022 15:37:43
**/
#include <bits/stdc++.h>
using namespace std;
struct node {
long long dp[2][2];
long long L, R;
};
const int MAX = 200000;
const long long inf = 1e10;
long long a[MAX];
node st[4 * MAX];
int sgn(long long x) {
return (x < 0 ? -1 : (x == 0 ? 0 : 1));
}
node merge(node l, node r) {
node ret;
ret.L = l.L;
ret.R = r.R;
for (int i = 0; i < 2; i++) {
for (int j = 0; j < 2; j++) {
ret.dp[i][j] = -inf;
}
}
for (int i = 0; i < 2; i++) {
for (int j = 0; j < 2; j++) {
if (i == 1 && j == 1 && sgn(l.R) != sgn(r.L)) {
continue;
}
for (int ii = 0; ii < 2; ii++) {
for (int jj = 0; jj < 2; jj++) {
ret.dp[ii][jj] = max(ret.dp[ii][jj], l.dp[ii][i] + r.dp[j][jj]);
}
}
}
}
return ret;
}
void build(int node, int l, int r) {
if (l == r) {
for (int i = 0; i < 2; i++) {
for (int j = 0; j < 2; j++) {
st[node].dp[i][j] = -inf;
}
}
st[node].dp[0][0] = 0;
st[node].dp[1][1] = abs(a[l]);
st[node].L = st[node].R = a[l];
return;
}
int mid = l + r >> 1;
build(node * 2, l, mid);
build(node * 2 + 1, mid + 1, r);
st[node] = merge(st[node * 2], st[node * 2 + 1]);
}
void update(int node, int l, int r, int i) {
if (l == r) {
for (int i = 0; i < 2; i++) {
for (int j = 0; j < 2; j++) {
st[node].dp[i][j] = -inf;
}
}
st[node].dp[0][0] = 0;
st[node].dp[1][1] = abs(a[l]);
st[node].L = st[node].R = a[l];
return;
}
int mid = l + r >> 1;
if (i <= mid) {
update(node * 2, l, mid, i);
} else {
update(node * 2 + 1, mid + 1, r, i);
}
st[node] = merge(st[node * 2], st[node * 2 + 1]);
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n, q;
cin >> n >> q;
for (int i = 0; i < n; i++) {
cin >> a[i];
}
for (int i = 0; i < n - 1; i++) {
a[i] -= a[i + 1];
}
if (n > 1) {
build(1, 0, n - 2);
}
while (q--) {
int l, r, x;
cin >> l >> r >> x;
--l; --r;
if (n == 1) {
cout << 0 << '\n';
continue;
}
if (l > 0) {
a[l - 1] -= x;
update(1, 0, n - 2, l - 1);
}
a[r] += x;
if (r < n - 1) {
update(1, 0, n - 2, r);
}
long long ans = 0;
for (int i = 0; i < 2; i++) {
for (int j = 0; j < 2; j++) {
ans = max(ans, st[1].dp[i][j]);
}
}
cout << ans << '\n';
}
return 0;
}
Compilation message
Main.cpp: In function 'void build(int, int, int)':
Main.cpp:60:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
60 | int mid = l + r >> 1;
| ~~^~~
Main.cpp: In function 'void update(int, int, int, int)':
Main.cpp:78:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
78 | int mid = l + r >> 1;
| ~~^~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
1 ms |
340 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Correct |
1 ms |
340 KB |
Output is correct |
5 |
Correct |
1 ms |
336 KB |
Output is correct |
6 |
Correct |
1 ms |
340 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
1 ms |
340 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Correct |
1 ms |
340 KB |
Output is correct |
5 |
Correct |
1 ms |
336 KB |
Output is correct |
6 |
Correct |
1 ms |
340 KB |
Output is correct |
7 |
Correct |
5 ms |
852 KB |
Output is correct |
8 |
Correct |
5 ms |
856 KB |
Output is correct |
9 |
Correct |
5 ms |
852 KB |
Output is correct |
10 |
Correct |
4 ms |
852 KB |
Output is correct |
11 |
Correct |
7 ms |
852 KB |
Output is correct |
12 |
Correct |
4 ms |
852 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
1 ms |
340 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Correct |
1 ms |
340 KB |
Output is correct |
5 |
Correct |
1 ms |
336 KB |
Output is correct |
6 |
Correct |
1 ms |
340 KB |
Output is correct |
7 |
Correct |
5 ms |
852 KB |
Output is correct |
8 |
Correct |
5 ms |
856 KB |
Output is correct |
9 |
Correct |
5 ms |
852 KB |
Output is correct |
10 |
Correct |
4 ms |
852 KB |
Output is correct |
11 |
Correct |
7 ms |
852 KB |
Output is correct |
12 |
Correct |
4 ms |
852 KB |
Output is correct |
13 |
Correct |
595 ms |
35648 KB |
Output is correct |
14 |
Correct |
589 ms |
35664 KB |
Output is correct |
15 |
Correct |
516 ms |
35580 KB |
Output is correct |
16 |
Correct |
526 ms |
35608 KB |
Output is correct |
17 |
Correct |
543 ms |
35424 KB |
Output is correct |
18 |
Correct |
486 ms |
36220 KB |
Output is correct |