find the missing number in an array To find the missing number in an array we are perform following step :- First we initialize one array a with int value; Declare two int variable sum1 and sum2; Create one for loop and execute from 0 to less than array length size. Add the value a[i] with sum1 temp vaiable. Create another for loop and execute from 0 to last value of array variable. Add index value in temp sum2 variable. Now sum2 minus sum1 do,which result will be missing number. int mn = sum2 – sum1; public class MissingNumber { public static void main(String[] args) { int a[] = { 1, 2, 3, 5 }; int sum1 = 0; int sum2 = 0; for (int i = 0; i < a.length; i++) { sum1 = sum1 + a[i]; } for (int i = 0; i <= 5; i++) { sum2 = sum2 + i; } int mn = sum2 - sum1; System.out.println("MissingNumber are :- "+mn); } } Output :-MissingNumber are :- 4 find the missing number in an array Read More »