AMAZON INTERVIEW QUESTIONS

AMAZON INTERVIEW QUESTION--
QUESTION--
You have an array of size n with values ranging from 1 to n. Exactly one number is missed and one number is repeated. Find missing number and Repeated number.

SOLUTION --


#include
int main()
{
    int n,i;
    scanf("%d",&n);
    int arr[n];
    for(i=0;i
        scanf("%d",&arr[i]);
   int sum_of_digit=0;
   int sum_of_sqdigit=0;
    for(i=0;i
    {
        sum_of_digit+=arr[i];
        sum_of_sqdigit+=arr[i]*arr[i];
    }
    int sum_of_digit1=(n*(n+1))/2;
    int sum_of_sqdigit1=(n*(n+1)*(2*n+1))/6;
    int repeat_value=((sum_of_sqdigit-sum_of_sqdigit1)/(sum_of_digit-sum_of_digit1)+(sum_of_digit-sum_of_digit1))/2;
    int miss_value=((sum_of_sqdigit-sum_of_sqdigit1)/(sum_of_digit-sum_of_digit1)-(sum_of_digit-sum_of_digit1))/2;
    printf("repeated valu=%d\nmiss value=%d",repeat_value,miss_value);
    return 0;
}