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 (&lt100) 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 (&ltN) 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 (&gt0) 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 18

Sample Output:

9 4

#include<cstdio>
#include<vector>
using namespace std;
const int maxn = 110;
int hashtable[maxn] = {0};
vector<int> node[maxn];

void DFS(int index, int level){
 hashtable[level]++;
    for(int i = 0; i < node[index].size(); i++){
     DFS(node[index][i],level+1);    
    }
}

int main() {
    int n,m,father,child,k;
    scanf("%d%d",&n,&m);
    for(int i = 0 ; i < m; i++){
    scanf("%d%d",&father,&k);
        for(int j = 0; j < k; j++){
          scanf("%d",&child);
            node[father].push_back(child);
        }
    }
    DFS(1,1);
    int maxlevel = -1, maxvalue = 0;
    for(int i = 0; i < maxn; i++){
    if(maxvalue < hashtable[i]){
     maxvalue = hashtable[i];
        maxlevel = i;
    }
    }
    printf("%d %d",maxvalue,maxlevel);
    return 0;
}

 

BFS

#include <cstdio>
#include <vector>
#include <queue>

using namespace std;

const int maxn = 110;
int generation[maxn] = {0};

struct Node
{
    vector<int> childs;
}tree[maxn];

int max_generation = 0;
int max_index_generation = 0;

void BFS(int s)
{
    queue<int> que;
    que.push(s);

    int last = s;
    int tail = -1;
    int level = 1;
    int count = 0;

    while (!que.empty())
    {
        int top = que.front();
        que.pop();
        count++;

        if(tree[top].childs.size() != 0) {
            for(int i = 0; i < tree[top].childs.size(); ++i) {
                int child_idx = tree[top].childs[i];
                que.push(child_idx);

                tail = child_idx;
            }
        }

        if(top == last) {
            last = tail;
            if(count > max_generation) {
                max_generation = count;
                max_index_generation = level;
            }
            level++;
            count = 0;
        }
    }
    
}

int main()
{
    int n,m;
    scanf("%d%d",&n,&m);

    for(int i = 0 ; i < m; ++i) {
        int num = 0;
        int idx = 0;
        scanf("%d%d",&idx,&num);
        for(int j = 0; j < num; ++j) {
            int child_idx;
            scanf("%d",&child_idx);
            tree[idx].childs.push_back(child_idx);
        }
    }

    BFS(1);

    printf("%d %d\n", max_generation, max_index_generation);
    return 0;
}

 

BFS 2

#include <cstdio>
#include <vector>
#include <queue>

using namespace std;

const int maxn = 110;
int generation[maxn] = {0};

struct Node
{
    int level;
    vector<int> childs;
}tree[maxn];


void BFS(int s)
{
    queue<int> que;
    que.push(s);
    tree[s].level = 1;

    while (!que.empty())
    {
        int top = que.front();
        que.pop();
        if(tree[top].childs.size() != 0) {
            for(int i = 0; i < tree[top].childs.size(); ++i) {
                int child_idx = tree[top].childs[i];
                tree[child_idx].level = tree[top].level + 1;
                que.push(child_idx);
            }
        }
    }
    
}

int main()
{
    int n,m;
    scanf("%d%d",&n,&m);

    for(int i = 0 ; i < m; ++i) {
        int num = 0;
        int idx = 0;
        scanf("%d%d",&idx,&num);
        for(int j = 0; j < num; ++j) {
            int child_idx;
            scanf("%d",&child_idx);
            tree[idx].childs.push_back(child_idx);
        }
    }

    BFS(1);

    int generation_maxn = 0;
    int max_index = -1;
    for(int i = 1; i <= n; ++i) {
        generation[tree[i].level]++;
        if(generation_maxn < generation[tree[i].level]) {
            generation_maxn = generation[tree[i].level];
            max_index = tree[i].level;
        }
    }

    printf("%d %d\n", generation_maxn, max_index);
    return 0;
}