题目传送门
解题思路:
根据所给条件将题目编号和锦囊编号连边,然后跑二分图最大匹配。
AC代码:
1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 5 using namespace std; 6 7 int n,m,head[1005],tot,ans,g[1005],a[1005]; 8 bool vis[1005]; 9 struct kkk{ 10 int to,next; 11 }e[2005]; 12 13 inline void add(int x,int y) { 14 e[++tot].to = y; 15 e[tot].next = head[x]; 16 head[x] = tot; 17 } 18 19 inline bool find(int x) { 20 for(int i = head[x];i; i = e[i].next) { 21 int u = e[i].to; 22 if(vis[u]) continue; 23 vis[u] = 1; 24 if(g[u] == 0 || find(g[u])) { 25 g[u] = x; 26 a[x] = u; 27 return true; 28 } 29 } 30 return false; 31 } 32 33 int main() { 34 scanf("%d%d",&n,&m); 35 for(int i = 1;i <= m; i++) { 36 int x,y; 37 scanf("%d%d",&x,&y); 38 add(i,x); 39 add(i,y); 40 } 41 for(int i = 1;i <= n; i++) { 42 memset(vis,0,sizeof(vis)); 43 if(find(i)) ans++; 44 else break; 45 } 46 printf("%d ",ans); 47 for(int i = 1;i <= ans; i++) 48 printf("%d ",a[i]); 49 return 0; 50 }