Program to compare two fractions (original) (raw)

Last Updated : 20 May, 2026

Given a string **s containing two fractions **a/b and **c/d, compare them and return the **greater. If they are equal, then return "**equal".

**Note: The string s contains "**a/b, c/d"(fractions are separated by comma(,) & space( )).

**Examples :

**Input: s = "5/6, 11/45"
**Output: 5/6
**Explanation: 5/6=0.8333 and 11/45=0.2444, So 5/6 is a greater fraction.

**Input: s= "8/1, 8/1"
**Output: equal
**Explanation: We can see that both the fractions are same, so we'll return a string "equal".

Try It Yourself

Table of Content

[Naive Approach] Using Floating Point Division - O(1) Time O(1) Space
[Expected Approach] Using Cross Multiplication - O(1) Time O(1) Space

[Naive Approach] Using Floating Point Division - O(1) Time O(1) Space

The idea is to convert both fractions into decimal values and compare them.

C++ `

#include using namespace std;

// Function to compare two fractions string compareFrac(string &s) {

// Finding position of comma
int commaPos = s.find(',');

// Extracting both fractions
string s1 = s.substr(0, commaPos);
string s2 = s.substr(commaPos + 2);

// Finding position of '/'
int slash1 = s1.find('/');
int slash2 = s2.find('/');

// Extracting numerator and denominator
int a = stoi(s1.substr(0, slash1));
int b = stoi(s1.substr(slash1 + 1));

int c = stoi(s2.substr(0, slash2));
int d = stoi(s2.substr(slash2 + 1));

// Converting fractions into decimal values
double val1 = (double)a / b;
double val2 = (double)c / d;

// Comparing decimal values
if (val1 > val2)
    return s1;

if (val2 > val1)
    return s2;

return "equal";

}

// Driver Code int main() {

string s = "5/6, 11/45";

cout << compareFrac(s);

return 0;

}

C

#include <stdio.h> #include <stdlib.h> #include <string.h>

// Function to compare two fractions char* compareFrac(char* s) { // Finding position of comma char* commaPos = strchr(s, ',');

// Extracting both fractions
char s1[50];
char s2[50];

strncpy(s1, s, commaPos - s);
s1[commaPos - s] = '\0';

strcpy(s2, commaPos + 2);

// Variables for numerator and denominator
int a, b, c, d;

// Extracting numerator and denominator
sscanf(s1, "%d/%d", &a, &b);
sscanf(s2, "%d/%d", &c, &d);

// Converting fractions into decimal values
double val1 = (double)a / b;
double val2 = (double)c / d;

// Comparing decimal values
if (val1 > val2)
    return strdup(s1);

if (val2 > val1)
    return strdup(s2);

return strdup("equal");

}

// Driver Code int main() { char s[] = "5/6, 11/45";

printf("%s", compareFrac(s));

return 0;

}

Java

import java.util.*;

public class GfG { // Function to compare two fractions public static String compareFrac(String s) { // Finding position of comma int commaPos = s.indexOf(',');

    // Extracting both fractions
    String s1 = s.substring(0, commaPos);
    String s2 = s.substring(commaPos + 2);

    // Finding position of '/'
    int slash1 = s1.indexOf('/');
    int slash2 = s2.indexOf('/');

    // Extracting numerator and denominator
    int a = Integer.parseInt(s1.substring(0, slash1));
    int b = Integer.parseInt(s1.substring(slash1 + 1));

    int c = Integer.parseInt(s2.substring(0, slash2));
    int d = Integer.parseInt(s2.substring(slash2 + 1));

    // Converting fractions into decimal values
    double val1 = (double)a / b;
    double val2 = (double)c / d;

    // Comparing decimal values
    if (val1 > val2)
        return s1;

    if (val2 > val1)
        return s2;

    return "equal";
}

// Driver Code
public static void main(String[] args) {
    String s = "5/6, 11/45";
    System.out.println(compareFrac(s));
}

}

Python

def compareFrac(s):

# Finding position of comma
commaPos = s.find(',')

# Extracting both fractions
s1 = s[:commaPos]
s2 = s[commaPos + 2:]

# Finding position of '/'
slash1 = s1.find('/')
slash2 = s2.find('/')

# Extracting numerator and denominator
a = int(s1[:slash1])
b = int(s1[slash1 + 1:])

c = int(s2[:slash2])
d = int(s2[slash2 + 1:])

# Converting fractions into decimal values
val1 = a / b
val2 = c / d

# Comparing decimal values
if val1 > val2:
    return s1

if val2 > val1:
    return s2

return "equal"

Driver Code

if name == "main":

s = "5/6, 11/45"

print(compareFrac(s))

C#

using System;

class GfG { // Function to compare two fractions public static string compareFrac(string s) { // Finding position of comma int commaPos = s.IndexOf(',');

    // Extracting both fractions
    string s1 = s.Substring(0, commaPos);
    string s2 = s.Substring(commaPos + 2);

    // Finding position of '/'
    int slash1 = s1.IndexOf('/');
    int slash2 = s2.IndexOf('/');

    // Extracting numerator and denominator
    int a = int.Parse(s1.Substring(0, slash1));
    int b = int.Parse(s1.Substring(slash1 + 1));

    int c = int.Parse(s2.Substring(0, slash2));
    int d = int.Parse(s2.Substring(slash2 + 1));

    // Converting fractions into decimal values
    double val1 = (double)a / b;
    double val2 = (double)c / d;

    // Comparing decimal values
    if (val1 > val2)
        return s1;

    if (val2 > val1)
        return s2;

    return "equal";
}

// Driver Code
public static void Main() {
    string s = "5/6, 11/45";
    Console.WriteLine(compareFrac(s));
}

}

JavaScript

// Function to compare two fractions function compareFrac(s) { // Finding position of comma let commaPos = s.indexOf(',');

// Extracting both fractions
let s1 = s.substring(0, commaPos);
let s2 = s.substring(commaPos + 2);

// Finding position of '/'
let slash1 = s1.indexOf('/');
let slash2 = s2.indexOf('/');

// Extracting numerator and denominator
let a = parseInt(s1.substring(0, slash1));
let b = parseInt(s1.substring(slash1 + 1));

let c = parseInt(s2.substring(0, slash2));
let d = parseInt(s2.substring(slash2 + 1));

// Converting fractions into decimal values
let val1 = a / b;
let val2 = c / d;

// Comparing decimal values
if (val1 > val2)
    return s1;

if (val2 > val1)
    return s2;

return 'equal';

}

// Driver Code let s = '5/6, 11/45'; console.log(compareFrac(s));

**Time Complexity: O(1)
**Auxiliary Space: O(1)

[Expected Approach] Using Cross Multiplication - O(1) Time O(1) Space

The idea is to compare fractions using cross multiplication instead of division.

For two fractions a/b and c/d, compare a * d and b * c

If a * d > b * c, then the first fraction is greater.

If a * d < b * c, then the second fraction is greater.

Otherwise, both fractions are equal.