Chapter04_7_drill_PPPC++

chapter4_drill.cpp

#include "../../std_lib_facilities.h"

int main(){
    
    const string unit_cm = "cm";
    const string unit_m = "m";
    const string unit_in = "in";
    const string unit_ft = "ft";
    const double cm_per_m = 100;
    const double cm_per_in = 2.54;
    const double in_per_ft = 12;

    int count = 0;
    double n = 0.0;
    string unit = "x";
    double max = 0.0;
    double min = 0.0;
    
    cout << "値を単位（"<< unit_cm << ", " << unit_m << ", " << unit_in 
        << ", " << unit_ft << "）つきで入力する。「Ctrl-z」を入力したら終了する。\n";

    while(cin >> n >> unit){

        if(cin.fail()){
            cout << "input error. \n";
            break;
        }
        
        double tmp = 0.0;

        if(unit == unit_cm){
            tmp = n;
        }else if(unit == unit_m){
            tmp = n * cm_per_m;
            cout << n << unit_m << " == ";
        }else if(unit == unit_in){
            tmp = n * cm_per_in;
            cout << n <<  unit_in << " == ";
        }else if(unit == unit_ft){
            tmp = n * in_per_ft * cm_per_in;
            cout << n <<  unit_ft << " == ";
        }else{

        }
        cout << tmp << unit_cm;

        if(tmp < min){
            cout << " the smallest so far";
            min = tmp;
        }
        if(max < tmp){
            cout << " the largest so far";
            max = tmp;
        }

        cout << '\n';

        count++;
        if(count == 1){
            max = tmp;
            min = tmp;
        }
    }
    return 0;
}