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Description
Hardwoods (硬木) are the botanical (植物学的) group of trees that have broad leaves, produce a fruit or nut, and generally go dormant (休眠的) in the winter.
America's temperate (温和的) climates produce forests with hundreds of hardwood species (物种) -- trees that share certain biological (生物的) characteristics (特征). Although oak, maple and cherry (樱桃) all are types of hardwood trees, for example, they are different species. Together, all the hardwood species represent 40 percent of the trees in the United States.
On the other hand, softwoods (软木材), or conifers (针叶树), from the Latin word meaning "cone-bearing," have needles. Widely available US softwoods include cedar (雪松), fir, hemlock (铁杉), pine, redwood (红木树), spruce (云杉) and cypress (柏树). In a home, the softwoods are used primarily as structural (结构的) lumber (木材) such as 2x4s and 2x6s, with some limited decorative (装饰性的) applications.
Using satellite imaging technology, the Department of Natural Resources has compiled (编译) an inventory (存货) of every tree standing on a particular day. You are to compute the total fraction (分数) of the tree population represented by each species.
America's temperate (温和的) climates produce forests with hundreds of hardwood species (物种) -- trees that share certain biological (生物的) characteristics (特征). Although oak, maple and cherry (樱桃) all are types of hardwood trees, for example, they are different species. Together, all the hardwood species represent 40 percent of the trees in the United States.
On the other hand, softwoods (软木材), or conifers (针叶树), from the Latin word meaning "cone-bearing," have needles. Widely available US softwoods include cedar (雪松), fir, hemlock (铁杉), pine, redwood (红木树), spruce (云杉) and cypress (柏树). In a home, the softwoods are used primarily as structural (结构的) lumber (木材) such as 2x4s and 2x6s, with some limited decorative (装饰性的) applications.
Using satellite imaging technology, the Department of Natural Resources has compiled (编译) an inventory (存货) of every tree standing on a particular day. You are to compute the total fraction (分数) of the tree population represented by each species.
Input
Input (投入) to your program consists of a list of the species (物种) of every tree observed by the satellite; one tree per line. No species name exceeds (超过) 30 characters. There are no more than 10,000 species and no more than 1,000,000 trees.
Output
Print the name of each species represented in the population, in alphabetical (字母的) order, followed by the percentage of the population it represents, to 4 decimal (小数) places.
Sample Input
Red Alder Ash Aspen Basswood Ash Beech Yellow Birch Ash Cherry Cottonwood Ash Cypress Red Elm Gum Hackberry White Oak Hickory Pecan Hard Maple White Oak Soft Maple Red Oak Red Oak White Oak Poplan Sassafras Sycamore Black Walnut Willow
Sample Output
Ash 13.7931 Aspen 3.4483 Basswood 3.4483 Beech 3.4483 Black Walnut 3.4483 Cherry 3.4483 Cottonwood 3.4483 Cypress 3.4483 Gum 3.4483 Hackberry 3.4483 Hard Maple 3.4483 Hickory 3.4483 Pecan 3.4483 Poplan 3.4483 Red Alder 3.4483 Red Elm 3.4483 Red Oak 6.8966 Sassafras 3.4483 Soft Maple 3.4483 Sycamore 3.4483 White Oak 10.3448 Willow 3.4483 Yellow Birch 3.4483
题意：给出很多字符串，求出每个字符串出现的概率，按字典序输出，题意很简单，正常做法就是字典树计数；
ps：为了偷懒特意百度map的用法，（map用的不熟练）
注意输入流和输出流的使用，输出是G++用.f，C++用.lf
getline(cin,s),s需要是string，需要引入string头文件，std::string空间引入
cin.getline适合你知道读入大小，固定char数组，速度快
getline(cin,s)不需要指定大小，但速度慢、生成的文件大，适合偷懒用
cin.getline适合你知道读入大小，固定char数组，速度快
getline(cin,s)不需要指定大小，但速度慢、生成的文件大，适合偷懒用
还要注意用longlong
#include <iostream>
#include<cstring>
#include<map>
#include<cstdio>
using namespace std;int main()
{//ios::sync_with_stdio(false);//曾快速度的map<string,int >mp;string x;long long ans=0;while(getline(cin,x)){ans++;mp[x]++;}map<string,int >::iterator it=mp.begin();while(it!=mp.end()){printf("%s ",it->first.c_str());printf("%.4f\n",it->second*100.0/ans);++it;}return 0;
}
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