2013年省赛I题 Thrall’s Dream

2013年省赛I题
判断单向联通，用bfs
剪枝：从小到大跑，如果遇到之前跑过的点（也就是编号小于当前点的点），就o(n)传递关系。

bfs

 #include<iostream>
 #include<cstdio>
 #include<queue>
 #include<algorithm>
 #include<cmath>
 #include<ctime>
 #include<set>
 #include<map>
 #include<stack>
 #include<cstring>
 #define inf 2147483647
 #define ls rt<<1
 #define rs rt<<1|1
 #define lson ls,nl,mid,l,r
 #define rson rs,mid+1,nr,l,r
 #define N 100010
 #define For(i,a,b) for(int i=a;i<=b;i++)
 #define p(a) putchar(a)
 #define g() getchar()

 using namespace std;
 int T;
 int n,m,cnt;
 int x,y;
 bool b[][];
 struct node{
     int n;
     node *next;
 }*e[];

 queue<int>q;

 void in(int &x){
     int y=;
     char c=g();x=;
     while(c<''||c>''){
         if(c=='-')y=-;
         c=g();
     }
     while(c<=''&&c>=''){
         x=(x<<)+(x<<)+c-'';c=g();
     }
     x*=y;
 }
 void o(int x){
     if(x<){
         p('-');
         x=-x;
     }
     if(x>)o(x/);
     p(x%+'');
 }

 void push(int x,int y){
     node *p;
     p=new node();
     p->n=y;
     if(!e[x])
         e[x]=p;
     else{
         p->next=e[x]->next;
         e[x]->next=p;
     }
 }

 void bfs(int x){
     q.push(x);
     while(!q.empty()){
         int t=q.front();
         q.pop();
         if(t<x){
             For(i,,n)
                 if(b[t][i])
                     b[x][i]=;
         }
         else{
             for(node *i=e[t];i;i=i->next)
                 if(!b[x][i->n]){
                     b[x][i->n]=;
                     q.push(i->n);
                 }
         }
     }
 }

 bool judge(){
     For(i,,n)
         For(j,i+,n)
             if(!b[i][j]&&!b[j][i])
                 return ;
     return ;
 }

 void clear(){
     memset(b,,sizeof(b));
     For(i,,)
         e[i]=;
 }

 int main(){
     in(T);
     while(T--){
         clear();
         in(n);in(m);
         For(i,,m){
             in(x);in(y);
             push(x,y);
         }
         For(i,,n)
             bfs(i);
         printf("Case %d: ",++cnt);
         if(judge())
             printf("Kalimdor is just ahead\n");
         else
             printf("The Burning Shadow consume us all\n");
     }
     return ;
 }

dfs更好写，队友比赛的时候不知道为啥T了

 #include<iostream>
 #include<cstdio>
 #include<queue>
 #include<algorithm>
 #include<cmath>
 #include<ctime>
 #include<set>
 #include<map>
 #include<stack>
 #include<cstring>
 #define inf 2147483647
 #define ls rt<<1
 #define rs rt<<1|1
 #define lson ls,nl,mid,l,r
 #define rson rs,mid+1,nr,l,r
 #define N 100010
 #define For(i,a,b) for(int i=a;i<=b;i++)
 #define p(a) putchar(a)
 #define g() getchar()

 using namespace std;
 int T;
 int n,m,cnt;
 int x,y;
 bool b[][];
 struct node{
     int n;
     node *next;
 }*e[];

 queue<int>q;

 void in(int &x){
     int y=;
     char c=g();x=;
     while(c<''||c>''){
         if(c=='-')y=-;
         c=g();
     }
     while(c<=''&&c>=''){
         x=(x<<)+(x<<)+c-'';c=g();
     }
     x*=y;
 }
 void o(int x){
     if(x<){
         p('-');
         x=-x;
     }
     if(x>)o(x/);
     p(x%+'');
 }

 void push(int x,int y){
     node *p;
     p=new node();
     p->n=y;
     if(e[x]==NULL)
         e[x]=p;
     else{
         p->next=e[x]->next;
         e[x]->next=p;
     }
 }

 // void bfs(int x){
 //     q.push(x);
 //     while(!q.empty()){
 //         int t=q.front();
 //         q.pop();
 //         if(t<x){
 //             For(i,1,n)
 //                 if(b[t][i])
 //                     b[x][i]=1;
 //         }
 //         else{
 //             for(node *i=e[t];i;i=i->next)
 //                 if(!b[x][i->n]){
 //                     b[x][i->n]=1;
 //                     q.push(i->n);
 //                 }
 //         }
 //     }
 // }

 void dfs(int x,int f){
     for(node *i=e[x];i;i=i->next)
         if(!b[f][i->n]){
             b[f][i->n]=;
             dfs(i->n,f);
         }
 }

 bool judge(){
     For(i,,n)
         For(j,i+,n)
             if(!b[i][j]&&!b[j][i])
                 return ;
     return ;
 }

 void clear(){
     memset(b,,sizeof(b));
     For(i,,)
         e[i]=;
 }

 int main(){
     in(T);
     while(T--){
         clear();
         in(n);in(m);
         For(i,,m){
             in(x);in(y);
             push(x,y);
         }
         For(i,,n)
             dfs(i,i);
         printf("Case %d: ",++cnt);
         if(judge())
             printf("Kalimdor is just ahead\n");
         else
             printf("The Burning Shadow consume us all\n");
     }
     return ;
 }