1079 Total Sales of Supply Chain（37行代码+详细注释）

分数 25

全屏浏览题目

作者 CHEN, Yue

单位 浙江大学

A supply chain is a network of retailers（零售商）, distributors（经销商）, and suppliers（供应商）-- everyone involved in moving a product from supplier to customer.

Starting from one root supplier, everyone on the chain buys products from one's supplier in a price P and sell or distribute them in a price that is r% higher than P. Only the retailers will face the customers. It is assumed that each member in the supply chain has exactly one supplier except the root supplier, and there is no supply cycle.

Now given a supply chain, you are supposed to tell the total sales from all the retailers.

Input Specification:

Each input file contains one test case. For each case, the first line contains three positive numbers: N (≤105), the total number of the members in the supply chain (and hence their ID's are numbered from 0 to N−1, and the root supplier's ID is 0); P, the unit price given by the root supplier; and r, the percentage rate of price increment for each distributor or retailer. Then N lines follow, each describes a distributor or retailer in the following format:

Ki​ ID[1] ID[2] ... ID[Ki​]

where in the i-th line, Ki​ is the total number of distributors or retailers who receive products from supplier i, and is then followed by the ID's of these distributors or retailers. Kj​ being 0 means that the j-th member is a retailer, then instead the total amount of the product will be given after Kj​. All the numbers in a line are separated by a space.

Output Specification:

For each test case, print in one line the total sales we can expect from all the retailers, accurate up to 1 decimal place. It is guaranteed that the number will not exceed 1010.

Sample Input:

10 1.80 1.00
3 2 3 5
1 9
1 4
1 7
0 7
2 6 1
1 8
0 9
0 4
0 3

Sample Output:

42.4

代码长度限制

16 KB

时间限制

250 ms

内存限制

64 MB

#include
using namespace std;
const int N=100005;
int n;
double p,r;
int leaf[N];//保存叶子结点的产品数 
vectorv[N];//用于保存非叶节点的孩子结点 
void dfs(int u,int h,double &sum){
    if(leaf[u]){//若是叶子结点 
        sum+=p*pow((1+r/100),h)*leaf[u];//将价格加到sum里 
    }
    for(int j=0;j         dfs(v[u][j],h+1,sum);
    }
    return ;
}
int main(){
    cin>>n>>p>>r;
    for(int i=0;i         int k;
        cin>>k;
        if(k==0){//k为0表示叶结点 
            int p;
            cin>>p;
            leaf[i]=p;//记录叶结点的产品数 
        }
        while(k--){//k不为0，记录孩子结点 
            int kid;
            cin>>kid;
            v[i].push_back(kid);
        }
    }
    double sum=0.0;
    dfs(0,0,sum);//深度遍历 
    printf("%.1f\n",sum);//输出 
    return 0;
}