Question

How to display histogram of character occurrences in text file with C++

Answer 1

#include <iostream>
#include <fstream>

using std::cout;
using std::endl;

int main()
{
	std::ifstream ifs("d:\\data.txt");

	int letters[255];
	char ch;

	for (int i = 0; i < 255; i++) letters[i] = 0;

	while (!ifs.eof()) {
		ifs >> ch;
		if (ch != '\n') {
			letters[int(ch)]++;
		}
	}

	ifs.close();

	for (int i = 0; i < 255; i++) {
		if (letters[i] != 0) {
			cout << (char)(i) << ": " << letters[i] << " ";
			for (int j = 0; j < letters[i]; j++)
				cout << "*";
			cout << endl;
		}
	}

	return 0;
}

/*
run:

#: 1 *
+: 2 **
a: 2 **
c: 3 ***
h: 2 **
j: 1 *
n: 2 **
o: 1 *
p: 3 ***
t: 1 *
v: 1 *
y: 1 *

*/

 

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