Accelerated C++ Exercises Ch4

4-2

Write a program to calculate the squares of int values up to 100. The program should write two columns: The first lists the value; the second contains the square of that value. Use setw (described above) to manage the output so that the values line up in columns.

#include <iostream>#include <vector>#include <string>using std::cout;using std::cin;using std::endl;using std::vector;using std::string;int main(){    vector<int>origin;    vector<int>calculated;    typedef vector<int>::size_type counts_sz;    int data;    int data_len;    int maxlen = 0;    cout << "input data:" << endl;// read all data and write down the maxlen    while (cin>>data)    {        origin.push_back(data);        calculated.push_back(data*data);        data_len = 1;        while ((data /= 10) > 0)        {            data_len++;        }        maxlen = maxlen > data_len ? maxlen : data_len;        cout << "input next:" << endl;    }// display all data    for (counts_sz i = 0; i != origin.size(); i++)    {        data_len = 1;        data = origin[i];        while ((data /= 10) > 0)        {            data_len++;        }        cout << origin[i]            << string(maxlen + 1 - data_len, ' ')            << calculated[i]            << endl;    }    system("pause");}