Check whether triangle is valid or not if sides are given

Given three sides, check whether triangle is valid or not. 
Examples: 

Input :  a = 7, b = 10, c = 5 
Output : Valid

Input : a = 1 b = 10 c = 12 
Output : Invalid

Approach: A triangle is valid if sum of its two sides is greater than the third side. If three sides are a, b and c, then three conditions should be met. 

1.a + b > c 
2.a + c > b 
3.b + c > a  

C++

// C++ program to check if three sides form a triangle or not
#include <bits/stdc++.h>
using namespace std;

// function to check if three sider form a triangle or not
bool checkValidity(int a, int b, int c)
{
    // check condition
    if (a + b <= c || a + c <= b || b + c <= a)
        return false;
    else
        return true;
}

// Driver function
int main()
{
    int a = 7, b = 10, c = 5;
    if (checkValidity(a, b, c))
        cout << "Valid";
    else
        cout << "Invalid";
}

// This code is contributed by Aditya Kumar (adityakumar129)

C

// C program to check if three sides form a triangle or not
#include <stdio.h>
#include <stdbool.h>

// function to check if three sider form a triangle or not
bool checkValidity(int a, int b, int c)
{
    // check condition
    if (a + b <= c || a + c <= b || b + c <= a)
        return false;
    return true;
}

// Driver function
void main()
{
    int a = 7, b = 10, c = 5;
    if (checkValidity(a, b, c))
        printf("Valid");
    else
        printf("Invalid");
}

// This code is contributed by Aditya Kumar (adityakumar129)

Java

// Java program to check validity of any triangle

public class GFG {
    // Function to calculate for validity
    public static int checkValidity(int a, int b, int c)
    {
        // check condition
        if (a + b <= c || a + c <= b || b + c <= a)
            return 0;
        else
            return 1;
    }

    // Driver function
    public static void main(String args[])
    {
        int a = 7, b = 10, c = 5;
        // function calling and print output
        if ((checkValidity(a, b, c)) == 1)
            System.out.print("Valid");
        else
            System.out.print("Invalid");
    }
}

// This code is contributed by Aditya Kumar (adityakumar129)

Python3

# Python3 program to check if three
# sides form a  triangle or not

# function to check if three sides
# form a triangle or not
def checkValidity(a, b, c):

    # check condition
    if (a + b <= c) or (a + c <= b) or (b + c <= a) :
        return False
    else:
        return True

# driver code
a = 7
b = 10
c = 5
if checkValidity(a, b, c):
    print("Valid")
else:
    print("Invalid")

C#

// C# program to check
// validity of any triangle
using System;

class GFG {

    // Function to calculate for validity
    public static int checkValidity(int a, int b,
                                    int c)
    {

        // check condition
        if (a + b <= c || a + c <= b ||
                            b + c <= a)
            return 0;
        else
            return 1;
    }

    // Driver code
    public static void Main()
    {
        int a = 7, b = 10, c = 5;

        // function calling and print output
        if ((checkValidity(a, b, c)) == 1)
          Console.Write("Valid");
        else
          Console.Write("Invalid");

    }
}

// This code is contributed by Nitin Mittal.

PHP

<?php
// PHP program to check if three
// sides form a triangle or not

// function to check if three sider
// form a triangle or not
function checkValidity($a, $b, $c)
{

    // check condition
    if ($a + $b <= $c ||
        $a + $c <= $b ||
        $b + $c <= $a)
        return false;
    else
        return true;
}

    // Driver Code
    $a = 7;
    $b = 10;
    $c = 5;

    if (checkValidity($a, $b, $c))
        echo "Valid";
    else
        echo "Invalid";

// This code is contributed by nitin mittal.
?>

Javascript

<script>

// Javascript program to check if three
// sides form a triangle or not

// function to check if three sider
// form a triangle or not
function checkValidity(a, b, c)
{
    // check condition
    if (a + b <= c || a + c <= b || b + c <= a)
        return false;
    else
        return true;
}

// Driver function

    let a = 7, b = 10, c = 5;

    if (checkValidity(a, b, c))
        document.write("Valid");
    else
        document.write("Invalid");

// This code is contributed by Mayank Tyagi

</script>

Output

Valid

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