Problem Statement

1Problem Description : Write Algorithm, Flowchart and Program to Add Three Integers
2
3Example 1 : 
4  Input  : num1 = 3, num2 = 7 and num3 = 5
5  Output : 15
6  Explanation : sum of 3, 7 and 5 results to 15
7
8Example 2 : 
9  Input  : num1 = 12, num2 = 7 and num3 = 1
10  Output : 20
11  Explanation : sum of 12, 7 and 1 results to 20

Algorithm

1Input : Three numbers num1, num2 and num3
2
3Step 1: Start
4
5Step 2: Declare sum to 0  
6        (This is optional step, during step5 
7        we can add declaration and assign directly as well)
8
9Step 3: Read number num1
10
11Step 4: Read number num2
12
13Step 5: Read number num3
14
15Step 5: Add num1, num2 and num3 and assign result to variable sum
16
17Step 6: Print sum
18
19Step 7: Stop
20
21Output: Sum of num1, num2 and num3 

Flowchart

Code Implementation

1import java.util.Scanner;
2
3public class SumThreeNumbers {
4
5    public static void main(String[] args) {
6        Scanner sc = new Scanner(System.in);
7
8        System.out.print("Enter num1: \n");
9        int num1 = sc.nextInt();
10
11        System.out.print("Enter num2: \n");
12        int num2 = sc.nextInt();
13
14        System.out.print("Enter num3: \n");
15        int num3 = sc.nextInt();
16
17        int sum = num1 + num2 + num3 ;
18        System.out.printf("sum of %d, %d, %d = %d \n", num1, num2, num3, sum);
19    }
20}

Output 1 :

1Enter num1: 12
2Enter num2: 7 
3Enter num3: 1 
412 + 7 + 1 = 20

Output 2 :

1Enter num1: 3
2Enter num2: 7 
3Enter num3: 5 
43 + 7 + 5 = 15