Submission #5646976

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Source Code Expand

#include <algorithm>
#include <cstring>
#include <cstdio>
int val[100005], app[25], seq[25];
int dp[100005], pop[100005], sum[100005];
int main()
{
	// freopen("E.in", "r", stdin);
	int n, m = 0, ans = 0;
	scanf("%d", &n);
	for (int i = 1; i < n; i++)
	{
		int u, v, w;
		scanf("%d%d%d", &u, &v, &w);
		val[u] ^= w;
		val[v] ^= w;
	}
	for (int i = 0; i < n; i++)
		app[val[i]]++;
	for (int i = 1; i < 16; i++)
	{
		ans += app[i] >> 1;
		if (app[i] & 1)
			seq[m++] = i;
	}
	for (int i = 1; i < 1 << m; i++)
	{
		pop[i] = pop[i ^ (i & -i)] + 1;
		for (int j = 0; j < m; j++)
		{
			if (i & (1 << j))
				sum[i] ^= seq[j];
		}
	}
	memset(dp, 0x3f, sizeof(dp));
	dp[0] = 0;
	for (int i = 0; i + 1 < 1 << m; i++)
	{
		int rem = (1 << m) - 1 ^ i, low = rem & -rem;
		for (int j = rem ^ low; ; j = j - 1 & (rem ^ low))
		{
			int add = j | low;
			if (!sum[add])
				dp[i | add] = std::min(dp[i | add], dp[i] + pop[j]);
			if (!j)
				break;
		}
	}
	printf("%d\n", ans + dp[(1 << m) - 1]);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:10:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
                 ^
./Main.cpp:14:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d", &u, &v, &w);
                              ^

Judge Result