Genealogical tree
Time Limit: 1000MS | Memory Limit: 65536K | |||
Total Submissions: 4420 | Accepted: 2933 | Special Judge |
Description
The system of Martians' blood relations is confusing enough. Actually, Martians bud when they want and where they want. They gather together in different groups, so that a Martian can have one parent as well as ten. Nobody will be surprised by a hundred of children. Martians have got used to this and their style of life seems to them natural.
And in the Planetary Council the confusing genealogical system leads to some embarrassment. There meet the worthiest of Martians, and therefore in order to offend nobody in all of the discussions it is used first to give the floor to the old Martians, than to the younger ones and only than to the most young childless assessors. However, the maintenance of this order really is not a trivial task. Not always Martian knows all of his parents (and there's nothing to tell about his grandparents!). But if by a mistake first speak a grandson and only than his young appearing great-grandfather, this is a real scandal.
Your task is to write a program, which would define once and for all, an order that would guarantee that every member of the Council takes the floor earlier than each of his descendants.
And in the Planetary Council the confusing genealogical system leads to some embarrassment. There meet the worthiest of Martians, and therefore in order to offend nobody in all of the discussions it is used first to give the floor to the old Martians, than to the younger ones and only than to the most young childless assessors. However, the maintenance of this order really is not a trivial task. Not always Martian knows all of his parents (and there's nothing to tell about his grandparents!). But if by a mistake first speak a grandson and only than his young appearing great-grandfather, this is a real scandal.
Your task is to write a program, which would define once and for all, an order that would guarantee that every member of the Council takes the floor earlier than each of his descendants.
Input
The first line of the standard input contains an only
number N, 1 <= N <= 100 — a number of members of the Martian Planetary
Council. According to the centuries-old tradition members of the Council are
enumerated with the natural numbers from 1 up to N. Further, there are exactly N
lines, moreover, the I-th line contains a list of I-th member's children. The
list of children is a sequence of serial numbers of children in a arbitrary
order separated by spaces. The list of children may be empty. The list (even if
it is empty) ends with 0.
Output
The standard output should contain in its only line a
sequence of speakers' numbers, separated by spaces. If several sequences satisfy
the conditions of the problem, you are to write to the standard output any of
them. At least one such sequence always exists.
Sample Input
5 0 4 5 1 0 1 0 5 3 0 3 0
Sample Output
2 4 5 3 1
Source
题解: 知道一个数n, 然后n行,编号1到n, 每行输入几个数,该行的编号排在这几个数前面,输出一种符合要求的编号名次排序。
此题中的就看测试数据
0
4 5 1 0
1 0
5 3 0
3 0
可知1后面什么也没有,2后面有4,5,1;3后面有1;4后面有5,3;5后面有3;
即上图
#include<cstdio> #include<iostream> #include<stack> #include<cstdlib> using namespace std; #define N 101 int cnt,vis[N],du[N],e[N][N],a[N],n,m; stack<int>s; int main(){ scanf("%d",&n); for(int i=1;i<=n;i++){ int x; while(scanf("%d",&x)==1){ if(!x) break; e[i][x]=1; du[x]++; } } for(int i=1;i<=n;i++){ if(!du[i]){ s.push(i); vis[i]=1; a[++cnt]=i; } } while(!s.empty()){ int p=s.top(); s.pop(); for(int i=1;i<=n;i++){ if(e[p][i]){ du[i]--; } } for(int i=1;i<=n;i++){ if(!du[i]&&!vis[i]){ s.push(i); vis[i]=1; a[++cnt]=i; } } } for(int i=1;i<=cnt;i++){ printf("%d ",a[i]); } return 0; }