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Submission #140570

# Submission time Handle Problem Language Result Execution time Memory
140570 2019-08-03T14:57:44 Z luciocf Street Lamps (APIO19_street_lamps) C++14
40 / 100
 5000 ms 14224 KB 
#include <bits/stdc++.h>

using namespace std;

typedef pair<int, int> pii;

const int maxn = 3e5+10;

struct Op
{
	int type;
	int ind;
} query[maxn];

struct E
{
	int type;
	int l, r;
} event[maxn];

int n, q;

int last[maxn];
int ans[maxn];

int pai[maxn], peso[maxn];
int edge[maxn], nivel[maxn];

bool on[maxn];
bool mark[maxn];

void init(void)
{
	for (int i = 1; i <= n; i++)
		pai[i] = i, peso[i] = 1;
}

int Find(int x)
{
	if (pai[x] == x) return x;
	return Find(pai[x]);
}

void Join(int x, int y, int t)
{
	x = Find(x), y = Find(y);
	if (x == y) return;

	if (peso[x] < peso[y]) swap(x, y);

	pai[y] = x, peso[x] += peso[y];
	edge[y] = t;
}

int dfs(int u, int p)
{
	if (u == p) return 0;

	nivel[u] = dfs(pai[u], p)+1;
}

int lca(int u, int v)
{
	int ans = 0;

	while (u != v)
	{
		if (nivel[u] > nivel[v]) ans = max(ans, edge[u]), u = pai[u];
		else ans = max(ans, edge[v]), v = pai[v];
	}

	return ans;
}

void solve_small(void)
{
	for (int i = 1; i <= q; i++)
	{
		string op;
		cin >> op;

		if (op == "toggle")
		{
			int ind;
			scanf("%d", &ind);

			query[i] = {0, ind};
		}
		else
		{
			int l, r;
			scanf("%d %d", &l, &r);

			query[i] = {1, -1};

			int ans = 0;
			for (int j = 1; j <= n; j++)
				mark[j] = on[j];

			for (int j = 1; j <= i; j++)
			{
				if (query[j].type == 1)
				{
					bool ok = 1;
					for (int k = l; k < r; k++)
						if (!mark[k])
							ok = 0;

					if (ok) ans++;
				}
				else
				{

					bool ok = 1;
					for (int k = l; k < r; k++)
						if (!mark[k])
							ok = 0;

					if (ok) ans++;

					mark[query[j].ind] = !mark[query[j].ind];
				}
			}

			printf("%d\n", ans);
		}
	}
}

void solve_two(void)
{
	for (int i = 1; i <= q; i++)
	{
		if (event[i].type == 0)
		{
			int ind = event[i].l;

			on[ind] = !on[ind];

			if (!on[ind])
				ans[ind] += (i-last[ind]);

			last[ind] = i;
		}
		else
		{
			int l = event[i].l, r = event[i].r;

			int tot = ans[l];

			if (on[l]) tot += (i-last[l]);

			printf("%d\n", tot);
		}
	}
}

int main(void)
{
	scanf("%d %d", &n, &q);

	init();

	for (int i = 1; i <= n; i++)
	{
		char x;
		scanf(" %c", &x);

		if (x == '1')
		{
			on[i] = true;
			Join(i, i+1, 0);
		}
	}

	if (n <= 100 && q <= 100)
	{
		solve_small();
		return 0;
	}

	bool ok = 1;

	for (int i = 1; i <= q; i++)
	{
		string s;
		cin >> s;

		if (s == "toggle")
		{
			int ind;
			scanf("%d", &ind);

			event[i] = {0, ind, -1};

			Join(ind, ind+1, i);
		}
		else
		{
			int l, r;
			scanf("%d %d", &l, &r);

			event[i] = {1, l, r};

			if (r != l+1) ok = 0;
		}
	}

	if (ok)
	{
		solve_two();
		return 0;
	}

	for (int i = 1; i <= n; i++)
		dfs(i, Find(i));

	for (int i = 1; i <= q; i++)
	{
		if (event[i].type)
		{
			int l = event[i].l, r = event[i].r;

			int first = lca(l, r);

			if (first >= i || Find(l) != Find(r)) printf("0\n");
			else printf("%d\n", i-first);
		}
	}
}

Compilation message

street_lamps.cpp: In function 'void solve_two()':
street_lamps.cpp:147:24: warning: unused variable 'r' [-Wunused-variable]
    int l = event[i].l, r = event[i].r;
                        ^
street_lamps.cpp: In function 'int dfs(int, int)':
street_lamps.cpp:60:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
street_lamps.cpp: In function 'void solve_small()':
street_lamps.cpp:85:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d", &ind);
    ~~~~~^~~~~~~~~~~~
street_lamps.cpp:92:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d %d", &l, &r);
    ~~~~~^~~~~~~~~~~~~~~~~
street_lamps.cpp: In function 'int main()':
street_lamps.cpp:160:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &q);
  ~~~~~^~~~~~~~~~~~~~~~~
street_lamps.cpp:167:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf(" %c", &x);
   ~~~~~^~~~~~~~~~~
street_lamps.cpp:192:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d", &ind);
    ~~~~~^~~~~~~~~~~~
street_lamps.cpp:201:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d %d", &l, &r);
    ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 3 ms 376 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 3 ms 376 KB Output is correct
7 Correct 3 ms 376 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 245 ms 7968 KB Output is correct
2 Correct 241 ms 8184 KB Output is correct
3 Correct 248 ms 8272 KB Output is correct
4 Correct 309 ms 14144 KB Output is correct
5 Correct 313 ms 13432 KB Output is correct
6 Correct 297 ms 14224 KB Output is correct
7 Correct 285 ms 10328 KB Output is correct
8 Correct 295 ms 13184 KB Output is correct

Subtask #3
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 376 KB Output is correct
2 Incorrect 3 ms 376 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
0 / 20.0

# Verdict Execution time Memory Grader output
1 Execution timed out 5027 ms 376 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 3 ms 376 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 3 ms 376 KB Output is correct
7 Correct 3 ms 376 KB Output is correct
8 Correct 245 ms 7968 KB Output is correct
9 Correct 241 ms 8184 KB Output is correct
10 Correct 248 ms 8272 KB Output is correct
11 Correct 309 ms 14144 KB Output is correct
12 Correct 313 ms 13432 KB Output is correct
13 Correct 297 ms 14224 KB Output is correct
14 Correct 285 ms 10328 KB Output is correct
15 Correct 295 ms 13184 KB Output is correct
16 Correct 3 ms 376 KB Output is correct
17 Incorrect 3 ms 376 KB Output isn't correct
18 Halted 0 ms 0 KB -