oj.uz

Submission #447288

# Submission time Handle Problem Language Result Execution time Memory
447288 2021-07-25T20:14:21 Z socho Sjeckanje (COCI21_sjeckanje) C++14
110 / 110
 916 ms 38204 KB 
#include <bits/stdc++.h>
using namespace std;
void fast() {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
}
void ran() {
	srand(chrono::steady_clock::now().time_since_epoch().count());
}
long long get_rand() {
	long long a = rand();
	long long b = rand();
	return a * (RAND_MAX + 1ll) + b;
}
void usaco() {
	freopen("problem.in", "r", stdin); 
	freopen("problem.out", "w", stdout);
}
template<typename T>
using min_pq = priority_queue<T, vector<T>, greater<T>>;
// #define endl '\n'
// #define double long double
#define int long long
// const int MOD = 1000 * 1000 * 1000 + 7;
// const int MOD = 998244353;

int n, q;
const int MXN = 200005;
int arr[MXN];
int df[MXN];

struct info {
	
	int with[2][2] = {{0}}; // first and last, taken or not taken
	
	info() {
		with[0][0] = with[0][1] = with[1][0] = with[1][1] = 0;
	}
	
} seg[MXN * 4];

info get(int x) {
	info res;
	res.with[1][1] = abs(x);
	return res;
}

int sg(int x) {
	if (x > 0) return 1;
	if (x < 0) return -1;
	return 0;
}

info comb(info l, info r, int m) {
	
	info res;
	
	bool cantog = (df[m] <= 0 && df[m+1] <= 0) || (df[m] >= 0 && df[m+1] >= 0);
	if (cantog) {
		
		for (int L=0; L<2; L++) {
			for (int R=0; R<2; R++) {
				for (int k=0; k<2; k++) for (int m=0; m<2; m++) {
					res.with[L][R] = max(res.with[L][R], l.with[L][k] + r.with[m][R]);
				}
			}
		}
		
		
		
	}
	else {
		
		for (int L=0; L<2; L++) {
			for (int R=0; R<2; R++) {
				for (int k=0; k<2; k++) for (int m=0; m<2; m++) {
					if (k == 1 && m == 1) continue;
					else res.with[L][R] = max(res.with[L][R], l.with[L][k] + r.with[m][R]);
				}
			}
		}
		
	}
	
	return res;
	
}

void build(int ind, int l, int r) {
	if (l == r) {
		seg[ind] = get(df[l]);
		return;
	}
	int m = (l + r) / 2;
	build(ind*2, l, m);
	build(ind*2+1, m+1, r);
	seg[ind] = comb(seg[ind*2], seg[ind*2+1], m);
}

void update(int ind, int l, int r, int pos) {
	if (l == r) {
		seg[ind] = get(df[l]);
		return;
	}
	int m = (l + r) / 2;
	if (pos <= m) update(ind*2, l, m, pos);
	else update(ind*2+1, m+1, r, pos);
	seg[ind] = comb(seg[ind*2], seg[ind*2+1], m);
}

int best() {
	int a = 0;
	for (int i=0; i<2; i++) for (int j=0; j<2; j++) a = max(a, seg[1].with[i][j]);
	return a;
}

signed main() {

	ran(); fast();

	cin >> n >> q;
	for (int i=1; i<=n; i++) cin >> arr[i];
	
	if (n == 1) {
		for (int i=0; i<q; i++) cout << 0 << endl;
		exit(0);
	}
	
	for (int i=1; i<n; i++) df[i] = arr[i+1] - arr[i];

	build(1, 1, n-1);
	
	while (q--) {
		int l, r, k;
		cin >> l >> r >> k;
		if (l > 1) {
			df[l-1] += k;
			update(1, 1, n-1, l-1);
		}
		if (r < n) {
			df[r] -= k;
			update(1, 1, n-1, r);
		}
		cout << best() << endl;
		
	}

}

Compilation message

Main.cpp: In function 'void usaco()':
Main.cpp:15:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |  freopen("problem.in", "r", stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:16:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |  freopen("problem.out", "w", stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 25292 KB Output is correct
2 Correct 11 ms 25336 KB Output is correct
3 Correct 11 ms 25292 KB Output is correct
4 Correct 11 ms 25380 KB Output is correct
5 Correct 11 ms 25316 KB Output is correct
6 Correct 11 ms 25292 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 25292 KB Output is correct
2 Correct 11 ms 25336 KB Output is correct
3 Correct 11 ms 25292 KB Output is correct
4 Correct 11 ms 25380 KB Output is correct
5 Correct 11 ms 25316 KB Output is correct
6 Correct 11 ms 25292 KB Output is correct
7 Correct 20 ms 25548 KB Output is correct
8 Correct 20 ms 25548 KB Output is correct
9 Correct 22 ms 25548 KB Output is correct
10 Correct 21 ms 25640 KB Output is correct
11 Correct 20 ms 25548 KB Output is correct
12 Correct 19 ms 25548 KB Output is correct

Subtask #3
55.0 / 55.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 25292 KB Output is correct
2 Correct 11 ms 25336 KB Output is correct
3 Correct 11 ms 25292 KB Output is correct
4 Correct 11 ms 25380 KB Output is correct
5 Correct 11 ms 25316 KB Output is correct
6 Correct 11 ms 25292 KB Output is correct
7 Correct 20 ms 25548 KB Output is correct
8 Correct 20 ms 25548 KB Output is correct
9 Correct 22 ms 25548 KB Output is correct
10 Correct 21 ms 25640 KB Output is correct
11 Correct 20 ms 25548 KB Output is correct
12 Correct 19 ms 25548 KB Output is correct
13 Correct 862 ms 37560 KB Output is correct
14 Correct 865 ms 37588 KB Output is correct
15 Correct 903 ms 37652 KB Output is correct
16 Correct 916 ms 37640 KB Output is correct
17 Correct 886 ms 37476 KB Output is correct
18 Correct 853 ms 38204 KB Output is correct