感觉总是无视拓扑排序也不太好，就来了2道模板题。。不造哪个时候又给忘了。。
codevs 1833
1 #include<bits/stdc++.h> 2 #define inc(i,l,r) for(int i=l;i<=r;i++) 3 #define dec(i,l,r) for(int i=l;i>=r;i--) 4 #define link(x) for(edge *j=h[x];j;j=j->next) 5 #define mem(a) memset(a,0,sizeof(a)) 6 #define inf 1e9 7 #define ll long long 8 #define succ(x) (1<<x) 9 #define NM 10000+5 10 #define nm 25000+5 11 using namespace std; 12 int read(){ 13 int x=0,f=1;char ch=getchar(); 14 while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();} 15 while(isdigit(ch))x=x*10+ch-'0',ch=getchar(); 16 return x*f; 17 } 18 struct edge{ 19 int t; 20 edge *next; 21 }e[nm],*h[NM],*o=e; 22 void add(int x,int y){ 23 o++;o->t=y;o->next=h[x];h[x]=o; 24 } 25 int n,m,v[NM],s,_x,_y; 26 queue<int >q; 27 void bfs(){ 28 inc(i,1,n)if(!v[i])q.push(i); 29 while(!q.empty()){ 30 int t=q.front();q.pop(); 31 link(t)if(v[j->t]){ 32 v[j->t]--; 33 if(!v[j->t])q.push(j->t); 34 } 35 } 36 } 37 int main(){ 38 n=read();m=read(); 39 inc(i,1,m){ 40 _x=read();_y=read(); 41 add(_x,_y);v[_y]++; 42 } 43 bfs(); 44 inc(i,1,n)if(v[i])s++; 45 if(!s)puts("o(∩_∩)o"); 46 else printf("T_T\n%d\n",s); 47 return 0; 48 }
hdu 1285 顺便学了优先队列
1 //#include<bits/stdc++.h> 2 #include<cstdio> 3 #include<algorithm> 4 #include<iostream> 5 #include<cstring> 6 #include<queue> 7 #define inc(i,l,r) for(int i=l;i<=r;i++) 8 #define dec(i,l,r) for(int i=l;i>=r;i--) 9 #define link(x) for(edge *j=h[x];j;j=j->next) 10 #define mem(a) memset(a,0,sizeof(a)) 11 #define inf 1e9 12 #define ll long long 13 #define succ(x) (1<<x) 14 #define NM 500+5 15 using namespace std; 16 int read(){ 17 int x=0,f=1;char ch=getchar(); 18 while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();} 19 while(isdigit(ch))x=x*10+ch-'0',ch=getchar(); 20 return x*f; 21 } 22 struct edge{ 23 int t; 24 edge *next; 25 }e[NM*NM],*h[NM],*o; 26 int n,m,v[NM],_x,_y,f; 27 struct cmp{ 28 bool operator ()(int &a,int &b){ 29 return a>b; 30 } 31 }; 32 priority_queue<int,vector<int>,cmp>q; 33 void add(int x,int y){ 34 o++;o->t=y;o->next=h[x];h[x]=o; 35 } 36 void bfs(){ 37 inc(i,1,n)if(!v[i])q.push(i); 38 while(!q.empty()){ 39 int t=q.top();q.pop();v[t]--; 40 if(f)putchar(' '); 41 printf("%d",t);f++; 42 link(t){ 43 v[j->t]--; 44 if(v[j->t]==0)q.push(j->t); 45 } 46 } 47 } 48 int main(){ 49 // freopen("data.in","r",stdin); 50 // freopen("test.out","w",stdout); 51 while(scanf("%d%d",&n,&m)!=EOF){ 52 mem(v);mem(h);o=e;f=0; 53 inc(i,1,m){ 54 _x=read();_y=read(); 55 add(_x,_y);v[_y]++; 56 } 57 bfs(); 58 printf("\n"); 59 } 60 return 0; 61 }
15noip D1T2貌似也可以拓扑？
