c++ find the max and min number in a column

Question

how do you find the maximum and minimum number from a column in a file? Then display the string associated with that number? ( without using arrays) example

column1: 10 15 105 7 45
string in colum 2: a b c d e

Just read the file into an internal data structure, e.g. a `std::map`. — Cheers and hth. - Alf, Sep 30 '16 at 22:49
yes, column. I just couldn't display it horizontally in this textboxs @pablo — Lola, Sep 30 '16 at 22:53
@lola96 it is easy to display the content of the file here, just wrap it in appropriate formatting markup. — Remy Lebeau, Sep 30 '16 at 22:59
Does the file have more than one column? If so, are the numbers/strings separated by spaces, commas, semicolons, ...? — Pedro Reis, Sep 30 '16 at 23:06
yes it has more than one column but I just need information from 2 of them @PedroReis — Lola, Sep 30 '16 at 23:19
Take a look at this: http://stackoverflow.com/questions/1120140/how-can-i-read-and-parse-csv-files-in-c and http://stackoverflow.com/questions/415515/how-can-i-read-and-manipulate-csv-file-data-in-c — Pablo, Sep 30 '16 at 23:55

score 1 · Answer 1 · answered Sep 30 '16 at 23:12

You just have to read the file line by line, remembering the minimum and maximum value and it's associated string you found till the end.

#include <fstream>
#include <limits>
#include <iostream>

void printMaxAndMin() {
  std::ifstream infile("file.txt");
  int curVal, 
      maxVal = std::numeric_limits<int>::min(), 
      minVal = std::numeric_limits<int>::max();
  std::string curStr, maxStr, minStr;

  while (infile >> curVal >> curStr) {
     maxStr = maxVal < curVal ? curStr : maxStr;
     maxVal = maxVal < curVal ? curVal : maxVal;

     minStr = minVal > curVal ? curStr : minStr;
     minVal = minVal > curVal ? curVal : minVal;
  }
  std::cout << "minimum: " << minVal << ", " << minStr << std::endl;
  std::cout << "maximum: " << maxVal << ", " << maxStr << std::endl;
}

c++ find the max and min number in a column

1 Answers1