Answer to Question #143402 in C++ for Bobby

Question

Given a nxm matrix containing the m temperatures of a city measured in n days, implement a function that takes in input this matrix and calculate the daily averages of temperatures, storing them in a vector. The carrier shall then be re-read and the minimum and maximum average temperature printed, specifying the day on which it occurred. (use just iostream)

Answer 1

#include <iostream>
#include <ctime>
#include <vector>
#include <iomanip>

using namespace std;

const unsigned int n = 7; //days
const unsigned int m = 8; //temperature measured every three hours within a day

/**The function takes in input a matrix and calculate the daily averages of temperatures, storing them in a vector.*/
vector<double> dailyAveragesOfTemperature(double matrix[n][m]) {
	vector<double> d;
	double sum;
	int i, j;
	for (i = 0; i < n; i++) {
		sum = 0;
		for (j = 0; j < m; j++) {
			sum += matrix[i][j];
		}
		d.push_back(sum / m);
	}
	return d;
}


int main()
{
	double matrix[n][m];

	srand(static_cast<unsigned int>(time(0)));

	int i, j;

	/**The Matrix is filled with random values from -40 to +40.*/
	/**At the same time, the matrix is displayed on the screen.*/
	cout << "         ";
	for (i = 0; i < m; i++) {
		cout << fixed << setw(5) << setprecision(2) << setfill('0') << i*3.0 << "   ";
	}
	cout << endl;
	cout << "       ";
	for (i = 0; i < m; i++) {
		cout << "--------";
	}
	cout << endl;
	for (i = 0; i < n; i++) {
		cout << fixed << "day " << i+1 << " |";
		for (j = 0; j < m; j++) {
			matrix[i][j] = (double)(rand()) / RAND_MAX * 80.0 - 40.0;
			cout << fixed << setw(7) << setprecision(2) << setfill(' ') << matrix[i][j] << " ";
		}
		cout << endl;
	}
	cout << endl;

	/**The vector is filled with average temperature values.*/
	vector<double> dAOT = dailyAveragesOfTemperature(matrix);


	cout << "The daily averages of temperatures : " << endl;
	for (i = 0; i < n; i++) {
		cout << fixed << "day " << i + 1 << " |";
		cout << fixed << setw(7) << setprecision(2) << setfill(' ') << dAOT.at(i);
		cout << endl;
	}
	cout << endl;

	double minT = dAOT.at(0), maxT = dAOT.at(0);
	int minDay = 0, maxDay = 0;

	for (i = 1; i < n; i++) {
		if (dAOT.at(i) > maxT) {
			maxT = dAOT.at(i);
			maxDay = i;
		}
		if (dAOT.at(i) < minT) {
			minT = dAOT.at(i);
			minDay = i;
		}
	}

	cout << fixed << setw(7) << setprecision(2) << setfill(' ') 
		<< "On the " << minDay+1 << " day, there was a minimum average daily temperature " << minT << endl;
	cout << "On the " << maxDay + 1 << " day, there was a maximum average daily temperature " << maxT << endl;
}