public static void main(String[] args) {

// Sum of Numbers in the Given Range

Scanner sc = new Scanner(System.in);

System.out.println("Enter lower range : ");

int lowerRange = sc.nextInt();

System.out.println("Enter upper range : ");

int upperRange = sc.nextInt();

int sum1 = 0, sum2 = 0, sum3 = 0;

// Technique 01 - For Loop

for (int i = lowerRange; i <= upperRange; i++) {

sum1 += i;

}

System.out.println("[For Loop] Sum of numbers from " + lowerRange + " to " + upperRange + " : " + sum1);

// Technique 02 - Formula

sum2 = (upperRange * (upperRange + 1) / 2) - (lowerRange * (lowerRange + 1) / 2) + lowerRange;

System.out.println("[Formula] Sum of numbers from " + lowerRange + " to " + upperRange + " : " + sum2);

// Technique 03 - Recursion

sum3 = sumOfRange(lowerRange, upperRange);

System.out.println("[Recursion] Sum of numbers from " + lowerRange + " to " + upperRange + " : " + sum3);

sc.close();

}

public static int sumOfRange(int lowerRange, int upperRange) {

if (upperRange == lowerRange)

return lowerRange;

return upperRange + sumOfRange(lowerRange, upperRange - 1);

}