我基本上试图使用一个数组,即从文件中读取的数据,然后使用该数组计算数据的均值和标准差.
我似乎无法得到正确的号码.
static public double[][] calcStats(String[][] x) throws IOException {
double[][] array = new double[7][2];
double total = 0, std_dev = 0, amount = 0;
int row2 = 0;
for (int row = 1; row < x.length; row++) {
array[row2][0] = (total);
array[row2][1] = Math.sqrt(amount);
amount = 0;
total = 0;
if (row >= 2) {
row2++;
}
for (int col = 1; col < x[row].length; col++) {
total += Integer.parseInt(x[row][col]);
if (col == 4) {
total = (total / …
Run Code Online (Sandbox Code Playgroud) 我是C++和矢量的新手,并试图尝试一些STL函数,我想知道为什么这不起作用.我猜它是因为我的第一个和最后一个位置,他们不被允许成为一个整体吗?
#include <cstdlib>
#include <vector>
#include <iostream>
using namespace std;
/*
*
*/
int main() {
const int lowest = 10;
const int highest = 99;
vector<int> scramble;
for (int i = 0; i < 20; i++){
scramble.push_back(lowest + rand() % (highest - lowest + 1));
cout << scramble.at(i) << endl;
}
int first = 0;
int last = 19;
cout << "The maximum value is: " << max_element(first, last);
}
Run Code Online (Sandbox Code Playgroud) 我想知道为什么这个while循环不允许我的程序终止?
据我所知(虽然我可能错了)条件while (cin >> line)
检查我的输入流是否为String然后运行我的循环,直到在输入中找不到其他字符串.然而,在测试我的代码后,我得到了正确的输出,但我的循环永远不会终止任何想法为什么?
#include <cstdlib>
#include <iostream>
#include <cctype>
using namespace std;
int main() {
string roman_digits[] = {"", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"};
string roman_tens [] = {"", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"};
string roman_hundreds [] = {"", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"};
string roman_thousands [] = {"", "M","MM", "MMM"};
string line;
char c;
cout << "Type in a Roman numeral: ";
// …
Run Code Online (Sandbox Code Playgroud)