hdu 6165 - 暴力dfs

题目链接:点击打开链接

题解思路:节点就1000，m就6000直接暴力肯定能过。

代码：

#include <iostream>
#include <cstdio>
#include<set>
#include<cstring>
#include<algorithm>
using namespace std;
typedef long long ll;
const int mx = 1e3+10;
struct node{
int y,nxt;
}Edge[mx<<3];
int n,m,head[mx],tot;
void AddEdge(int x,int y){
Edge[tot].y = y;
Edge[tot].nxt = head[x];
head[x] = tot++;
}
bool vis[mx][mx],vic[mx];
void dfs(int x,int fa){
for(int i=head[x];i!=-1;i=Edge[i].nxt){
int son = Edge[i].y;
if(vic[son]) continue;
vic[son] = 1;
vis[fa][son] = 1;
dfs(son,fa);
}
}
int main(){
int t;
scanf("%d",&t);
while(t--){
memset(head,-1,sizeof(head));
tot = 0;
scanf("%d%d",&n,&m);
int a,b;
for(int i=1;i<=m;i++){
scanf("%d%d",&a,&b);
AddEdge(a,b);
}
memset(vis,0,sizeof(vis));
for(int i=1;i<=n;i++){
memset(vic,0,sizeof(vic));
vic[i] = 1;
dfs(i,i);
}
int flag = 0;
for(int i=1;i<=n;i++){
for(int j=1;j<=n;j++){
if(j==i) continue;
if(!(vis[i][j]||vis[j][i])) flag = 1;
}
}
puts(flag?"Light my fire!":"I love you my love and our love save us!");
}
return 0;
}