1079 Total Sales of Supply Chain

Posted 2021-09-04 CSU迦叶

1. 这道题考察的是树的层次遍历，结点需要有层这个属性，对于我来说，难点在于什么时候给层赋值，看书后知道应该是在加入队列之前(不管是根节点还是之后所有节点)。

2. 一开始算得216，原因是把r直接加一当作底数，其实中间商没有那么黑。。。应该是除以100再加1当作底数。

AC代码

#include<cstdio>
#include<map>
#include<set>
#include<string>
#include<cstring>
#include<iostream>
#include<vector>
#include<stack>
#include<queue>
#include<algorithm>
#include<cmath>
typedef long long LL;

using namespace std;

const int maxn = 100010;

int n;//结点总数
double initPrice,rate;//出厂价和利率 
 
struct Node{
	int layer = 0;
	double price;
	vector<int> children;
	int amount;
}node[maxn];

bool appear[maxn] = {false};//用于寻找根节点

int findRoot(){
	for(int i=0;i<n;i++){
		if(!appear[i])return i;
	}
}

double layerOrder(int root){
	double sum = 0;
	queue<int> que;
	que.push(root);
	while(!que.empty()){
		int top = que.front();
		que.pop();
		int childN =  node[top].children.size();//当前结点的叶子结点数量 
		if(childN){//说明不是叶子结点 
			for(int i=0;i<childN;i++){
				int childI = node[top].children[i];
				node[childI].layer = node[top].layer+1;
				que.push(childI);
			}
		}else{//是叶子结点 
			sum += initPrice*node[top].amount*pow(rate/100+1,node[top].layer);
		}
	}
	
	return sum;
} 


int main(){
	
	scanf("%d %lf %lf",&n,&initPrice,&rate);	
	int childrenN,childIdx,amount;
	for(int i=0;i<n;i++){
		scanf("%d",&childrenN);
		if(childrenN){//说明不是叶子结点 
			while(childrenN--){
				scanf("%d",&childIdx);
				appear[childIdx] = true;
				node[i].children.push_back(childIdx);
			} 
		}else{
			scanf("%d",&amount);
			node[i].amount = amount; 
		}
	}
	
	int root = findRoot();
	
	double ans = layerOrder(root);
	
	printf("%.1f",ans); 
	 
	return 0;
}