PTA-算法笔记之树的遍历（BFS+DFS）_pta 先序遍历 李曲dfs

题目 A1079 Total Sales of Supply Chain

#include<bits/stdc++.h>
using namespace std;
int N;
double P,R;
double res = 0;
struct node{
    double data;//货物量
    vector<int> child;
}Node[100110];
void DFS(int index,int depth)
{
    //递归边界
    if(Node[index].child.size() == 0)
    {
        res += Node[index].data*pow(1+R,depth);
        return;
    }
    //递归式
    for(int i=0;i<Node[index].child.size();i++)
    {
        DFS(Node[index].child[i],depth+1);
    }
}
 
void BFS(int index)
{
    queue<int> q;
    q.push(index);
    int height = 0;
    while(!q.empty())
    {
 
        int n = q.size();
        for(int i=0;i<n;i++)
        {
            int temp = q.front();
            q.pop();
            if(Node[temp].child.size()==0)
            {
                res += Node[temp].data*pow(1+R,height);
            }
            for(int i=0;i<Node[temp].child.size();i++)
            {
                q.push(Node[temp].child[i]);
            }
 
        }
        height++;
 
    }
}
int main()
{
    cin>>N>>P>>R;
    R/=100;
    for(int i=0;i<N;i++)
    {
        int num;
        cin>>num;
        if(num==0)
        {
            cin>>Node[i].data;
        }
        else
        {
            for(int j=0;j<num;j++)
            {
                int x;
                cin>>x;
                Node[i].child.push_back(x);
            }
        }
 
    }
    BFS(0);
    printf("%.1lf",P*res);
    return 0;
}

A1090 Highest Price in Supply Chain (25分)

#include<bits/stdc++.h>
using namespace std;
const int maxn = 100010;
vector<int> child[maxn];
 
 
int n;
double p,r;
double res = 0;
int maxDepth = 0,num=0;
 
void DFS(int index,int depth)
{
    if(child[index].size()==0)
    {
        if(depth>maxDepth)
        {
            maxDepth = depth;
            num = 1;
        }
        else if(depth == maxDepth)
        {
            num++;
        }
        return;
    }
    for(int i=0;i<child[index].size();i++)
    {
        DFS(child[index][i],depth+1);
    }
}
 
void BFS(int index)
{
    queue<int> q;
    q.push(index);
    while(!q.empty())
    {
 
        int n = q.size();
        //每一次for循环就是层序遍历的一行
        for(int i=0;i<n;i++)
        {
            int temp = q.front();
            q.pop();
            for(int j=0;j<child[temp].size();j++)
            {
                q.push(child[temp][j]);
            }
        }
        maxDepth++;
        num = n;
    }
    maxDepth = maxDepth - 1;
}
int main()
{
    cin>>n>>p>>r;
    r/=100;
    int x,root;
    for(int i=0;i<n;i++)
    {
        cin>>x;
        if(x==-1)
        {
            root = i;
        }
        else
        {
            child[x].push_back(i);
        }
 
    }
    BFS(root);
    printf("%.2lf %d\n",p*pow(1+r,maxDepth),num);
    return 0;
}

A1094 The Largest Generation (25分)

#include<bits/stdc++.h>
using namespace std;
 
 
const int maxn = 101;
int hashTable[maxn] = {0};
int n,m;
vector<int> child[maxn];
 
 
void DFS(int index,int level)
{
    hashTable[level]++;
    for(int i=0;i<child[index].size();i++)
    {
        DFS(child[index][i],level+1);
    }
}
 
void BFS(int index,int level)
{
    queue<int> q;
    q.push(index);
    while(!q.empty())
    {
        int nsize = q.size();
        //每一次for循环就代表是层序遍历的一行
        for(int i=0;i<nsize;i++)
        {
            int temp = q.front();
            hashTable[level]++;
            q.pop();
            for(int j=0;j<child[temp].size();j++)
            {
                q.push(child[temp][j]);
            }
 
        }
        level++;
 
    }
}
 
int main()
{
    cin>>n>>m;
    for(int i=0;i<m;i++)
    {
        int id,k;
        cin>>id>>k;
        for(int j=0;j<k;j++)
        {
            int x;
            cin>>x;
            child[id].push_back(x);
        }
    }
    BFS(1,1);
    int maxLevel = -1,maxNum = 0;
    for(int i=1;i<maxn;i++)
    {
        if(hashTable[i]>maxNum)
        {
            maxNum = hashTable[i];
            maxLevel = i;
        }
    }
    cout<<maxNum<<" "<<maxLevel<<endl;
    return 0;
}

A1106 Lowest Price in Supply Chain (25分)

#include<bits/stdc++.h>
using namespace std;
struct node
{
    vector<int> child;
};
int n;
double p,r;
vector<node> v;
int num=0,minDepth=INT_MAX;
void DFS(int index,int depth)
{
    if(v[index].child.size()==0)    //到达叶子结点
    {
        if(depth<minDepth)
        {
            minDepth = depth;
            num = 1;
        }
        else if(depth==minDepth)
        {
            num++;
        }
        return;
    }
    for(int i=0; i < v[index].child.size(); i++)
    {
        DFS(v[index].child[i],depth+1);         //递归访问子节点
    }
}
int main()
{
    int k,child;
    cin>>n>>p>>r;
    v.resize(n);
    r /= 100;
    for(int i=0;i<n;i++)
    {
        cin>>k;
        if(k!=0)        //不是叶结点
        {
            for(int j=0;j<k;j++)
            {
                int x;
                cin>>x;
                v[i].child.push_back(x);
            }
        }
 
    }
    DFS(0,0);        //DFS入口
    printf("%.4f %d\n", p*pow(1+r,minDepth),num);
    return 0;
}

A1004 Counting Leaves (30分)

#include<bits/stdc++.h>
using namespace std;
 
 
const int maxn = 101;
int hashTable[maxn] = {0};
int n,m;
int level = 1;
vector<int> child[maxn];
 
 
 
void DFS(int index,int depth)
{
    if(child[index].size()==0)
    {
        hashTable[depth]++;
        level = max(depth,level);
        return;
    }
    for(int i=0;i<child[index].size();i++)
    {
        DFS(child[index][i],depth+1);
    }
}
 
void BFS(int index)
{
    queue<int> q;
    q.push(index);
    while(!q.empty())
    {
        int nsize = q.size();
        for(int i=0;i<nsize;i++)
        {
            int temp = q.front();
            if(child[temp].size()==0)
            {
                hashTable[level]++;
            }
            q.pop();
            for(int j=0;j<child[temp].size();j++)
            {
                q.push(child[temp][j]);
            }
 
        }
        level++;
 
    }
    level-=1;//最后会多加一行删掉
}
 
int main()
{
    cin>>n>>m;
    for(int i=0;i<m;i++)
    {
        int id,k;
        cin>>id>>k;
        for(int j=0;j<k;j++)
        {
            int x;
            cin>>x;
            child[id].push_back(x);
        }
    }
//    DFS(1,1);
    BFS(1);
    int maxLevel = -1,maxNum = 0;
    for(int i=1;i<=level;i++)
    {
 
        cout<<hashTable[i];
        if(i!=level)
        cout<<" ";
    }
 
    return 0;
}