搜索与图论：染色法判别二分图
搜索与图论：染色法判别二分图
- 题目描述
- 参考代码
题目描述
输入样例
4 4
1 3
1 4
2 3
2 4
输出样例
Yes
参考代码
#include <cstring>
#include <iostream>
#include <algorithm>using namespace std;const int N = 100010, M = 200010;int n, m;
int h[N], e[M], ne[M], idx;
int color[N];void add(int a, int b)
{e[idx] = b; ne[idx] = h[a]; h[a] = idx; idx++;
}bool dfs(int u, int c)
{color[u] = c;for (int i = h[u]; i != -1; i = ne[i]){int j = e[i];if (!color[j]){if (!dfs(j, 3 - c)) return false;}else if (color[j] == c) return false;}return true;
}int main()
{scanf("%d%d", &n, &m);memset(h, -1, sizeof h);while (m -- ){int a, b;scanf("%d%d", &a, &b);add(a, b); add(b, a);}bool flag = true;for (int i = 1; i <= n; i++)if (!color[i]){if (!dfs(i, 1)){flag = false;break;}}if (flag) puts("Yes");else puts("No");return 0;
}