编写一个C ++程序，该程序接受用户输入的一组数字，并输出最大值，最小值，平均值，中位数和众数。我们知道该模式可以是多个数字，因此请编写代码，以便在需要时输出多种模式。
输入整数，完成后输入字母。
-2 3 3 5 6 4 4 8 9 9 9 1 -2 10 10 10
Your numbers are: -2 -2 1 3 3 4 4 5 6 8 9 9 9 10 10 10
Max: 10
Min: -2
Average: 5.4375
Median: 5.5
Mode: 9 10 (3)
#include <iostream>
using namespace std;
void main()
{
double value, sum;
double average, minimum, maximum;
int count;
// initialise
sum = 0.0;
count = 0;
cout << "Enter a value: ";
cin >> value;
minimum = value;
maximum = value;
while (value >= 0.0)
{
// process value
sum += value;
count++;
if (value > maximum)
maximum = value;
else if (value < minimum)
minimum = value;
// get next value
cout << "Enter a value: ";
cin >> value;
}
if (count == 0)
cout << "No data entry" << endl;
else
{
average = sum / count;
cout << "There were " << count << " numbers" << endl;
cout << "Average was " << average << endl;
cout << "Minimum was " << minimum << endl;
cout << "Maximum was " << maximum << endl;
}
}
如果要使用STL，则可以编写如下内容（使用c ++ 11）：
#include <iostream>
#include <sstream>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <algorithm>
template<typename A, typename B>
std::pair<B,A> flip_pair(const std::pair<A,B> &p)
{
return std::pair<B,A>(p.second, p.first);
}
template<typename A, typename B>
std::multimap<B,A> flip_map(const std::map<A,B> &src)
{
std::multimap<B,A> dst;
std::transform(src.begin(), src.end(), std::inserter(dst, dst.begin()),
flip_pair<A,B>);
return dst;
}
int main() {
std::string line;
std::cout << "Enter numbers: ";
std::getline(std::cin, line);
std::istringstream iss(line);
std::vector<int> elements;
elements.reserve(1000);
std::string elem;
while (std::getline(iss, elem, ' ')) {
try {
elements.push_back(std::stoi(elem));
} catch (...) { }
}
double sum = 0.0;
std::size_t n = elements.size();
std::sort(elements.begin(), elements.end());
std::cout << "max=" << elements.back() << std::endl;
std::cout << "min=" << elements.front() << std::endl;
for (auto &x: elements) {
sum += x;
}
if (n == 0) return 1;
std::cout << "avg=" << sum / n << std::endl;
if (n == 1) {
std::cout << "med=" << elements[0] << std::endl;
}
else if (n % 2 == 0) {
std::size_t i = n/2;
std::cout << "med=" << (double)(elements[i] + elements[i-1]) / 2.0 << std::endl;
}
else {
std::cout << "med=" << elements[n/2] << std::endl;
}
std::set<int> elements_set;
for (auto &x: elements) {
elements_set.insert(x);
}
std::map<int, std::size_t> elements_count;
for (auto &x: elements_set) {
elements_count.insert(std::pair<int, std::size_t>(x, std::count(elements.begin(), elements.end(), x)));
}
std::multimap<std::size_t, int> count_elements;
count_elements = flip_map(elements_count);
std::cout << "mod: ";
std::size_t count_mod = count_elements.rbegin()->first;
for (auto &x: count_elements) {
if (x.first == count_mod) {
std::cout << x.second << ", ";
}
else { }
}
std::cout << "(" << count_mod << ")" << std::endl;
return 0;
}
中位数：
首先，您需要对数字进行排序。您可以将它们存储在数组中，然后使用排序算法，例如插入排序，选择排序等。对数组排序后，中位数是中间数。下面是用于插入排序实现的代码，假设您已将数字存储在arr[]中，并且length是数组的长度。
void insertion_sort(double arr[], int length) {
int i, j;
double tmp;
for (i = 1; i < length; i++) {
j = i;
while (j > 0 && arr[j - 1] > arr[j]) {
tmp = arr[j];
arr[j] = arr[j - 1];
arr[j - 1] = tmp;
j--;
}//end of while loop
print_array(arr,5);
}//end of for loop
}//end of insertion_sort.
模式：
您可以有一个计数器来跟踪阵列中的每个数字。最常见的一种是模式。
以下代码是您的代码的编辑版本，可以正常运行：
#include <iostream>
#include <map>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
double value, sum;
double average, minimum=(double)INFINITY, maximum=-(double)INFINITY, median;
map<int,int>modes;
vector<int>data;
int count,mxmode=0;
// initialise
sum = 0.0;
count = 0;
cout << "Enter a value (To end, press Ctrl+Z and Enter): ";
while (cin >> value)
{
// process value
sum += value;
count++;
if (value > maximum)
maximum = value;
if (value < minimum)
minimum = value;
modes[ value ]++;
mxmode = max(mxmode, modes[value]);
data.push_back(value);
// get next value
cout << "Enter a value (To end, press Ctrl+Z and Enter): ";
}
if (count == 0)
cout << "No data entry" << endl;
else
{
average = sum / count;
sort(data.begin(), data.end());
if(data.size()%2==0) median = ( data[ data.size()/2 - 1 ] + data[ data.size()/2 ] )/2.0;
else median = data[ data.size()/2 ];
cout << "There were " << count << " numbers" << endl;
cout << "Average was " << average << endl;
cout << "Minimum was " << minimum << endl;
cout << "Maximum was " << maximum << endl;
cout << "Median was " << median << endl;
cout << "Mode was";
for (auto &x: modes)
if(x.second == mxmode) cout<<" "<<x.first;
cout<<" ("<<mxmode<<")" << endl;
}
}
记住：
-std=c++11标志进行编译。EOF终止，或在控制台中，您可以通过按Ctrl + z然后按[[Enter终止它（如果您使用的操作系统与Windows不同，请使用相应的键）。” >