제출 #109201

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
109201		njchung99	전압 (JOI14_voltage)	C++14	100 / 100	227 ms	17528 KiB

voltage

#include<cstdio>
#include<algorithm>
#include<vector>
#include<cstring>
#include<stack>
using namespace std;
int n, m;
stack<int> st;
pair<int, int> a[200010];
vector<vector<int>> vt;
int par[100010];
int de[100010];
int visited[100010];
int used[200010];
int dp[100010];
int dp1[100010];
int dap = 0;
int odd = 0;
void dfs(int here) {
	st.push(here);
	visited[here] = 1;
	for (int i = 0; i < vt[here].size(); i++) {
		int id = vt[here][i];
		int next = a[id].first^a[id].second^here;
		if (!visited[next]) {
			used[id] = 1;
			par[next] = here;
			de[next] = de[here] + 1;
			dfs(next);
		}
	}
}
int main()
{
	scanf("%d %d", &n, &m);
	vt.resize(n + 1);
	for (int i = 0; i < m; i++) {
		int q, w;
		scanf("%d %d", &q, &w);
		vt[q].push_back(i);
		vt[w].push_back(i);
		a[i] = { q,w };
	}
	for (int i = 1; i <= n; i++) {
		if(!visited[i])
			dfs(i);
	}
	for (int i = 0; i < m; i++) {
		if (used[i])continue;
		int x = a[i].first;
		int y = a[i].second;
		if (de[x] < de[y])
			swap(x, y);
		if (de[x] % 2 == de[y] % 2) {
			dp[x]++; dp[y]--;
			odd++;
		}
		else {
			dp1[x]++; dp1[y]--;
		}
	}
	if (odd == 1)dap++;
	while (st.size()) {
		int t = st.top();
		int p = par[t];
		st.pop();
		if (par[t] && dp[t]==odd && dp1[t] == 0)dap++;
		dp[p] += dp[t];
		dp1[p] += dp1[t];
	}
	printf("%d\n", dap);
}

컴파일 시 표준 에러 (stderr) 메시지

voltage.cpp: In function 'void dfs(int)':
voltage.cpp:22:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < vt[here].size(); i++) {
                  ~~^~~~~~~~~~~~~~~~~
voltage.cpp: In function 'int main()':
voltage.cpp:35:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~~
voltage.cpp:39:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &q, &w);
   ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 35 / 35
• Subtask 4: 45 / 45