1094. The Largest Generation (25)
A family hierarchy is usually presented by a pedigree tree where all the nodes on the same level belong to the same generation. Your task is to find the generation with the largest population.
Input Specification:
Each input file contains one test case. Each case starts with two positive integers N (<100) which is the total number of family members in the tree (and hence assume that all the members are numbered from 01 to N), and M (<N) which is the number of family members who have children. Then M lines follow, each contains the information of a family member in the following format:
ID K ID[1] ID[2] ... ID[K]
where ID is a two-digit number representing a family member, K (>0) is the number of his/her children, followed by a sequence of two-digit ID's of his/her children. For the sake of simplicity, let us fix the root ID to be 01. All the numbers in a line are separated by a space.
Output Specification:
For each test case, print in one line the largest population number and the level of the corresponding generation. It is assumed that such a generation is unique, and the root level is defined to be 1.
Sample Input:23 13 21 1 23 01 4 03 02 04 05 03 3 06 07 08 06 2 12 13 13 1 21 08 2 15 16 02 2 09 10 11 2 19 20 17 1 22 05 1 11 07 1 14 09 1 17 10 1 18Sample Output:
9 4
解题思路:dfs遍历一遍树
#include <iostream>
#include <cstdio>
#include <cstring>
#include <string>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <cmath>
using namespace std;
#define LL long long
const int INF = 0x3f3f3f3f;
#define mod 1000000007
int n,m,ma;
int level[105];
int s[105],nt[105],e[105];
void dfs(int k,int p)
{
level[p]++;
if(level[p]>level[ma]) ma=level[p];
for(int i=s[k];~i;i=nt[i])
{
int ee=e[i];
dfs(ee,p+1);
}
}
int main()
{
while(~scanf("%d%d",&n,&m))
{
int id,k,cnt=1,p;
memset(level,0,sizeof level);
memset(s,-1,sizeof s);
for(int i=1;i<=m;i++)
{
scanf("%d%d",&id,&k);
for(int j=1;j<=k;j++)
{
scanf("%d",&p);
nt[cnt]=s[id],s[id]=cnt,e[cnt++]=p;
}
}
ma=-1;
dfs(1,1);
printf("%d %d\n",level[ma],ma);
}
return 0;
}