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SumOfDigits.c
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SumOfDigits.c
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#include<stdio.h>
int sumOfDigits(int);
int sumOfDigitsUsingTailRecursion(int, int);
int main(){
int num;
printf("Enter a number\n");
scanf("%d", &num);
printf("Sum of digits of %d is: %d\n", sumOfDigits(num));
printf("%Sum of digits of %d via Tail Recursion is: %d\n", sumOfDigitsUsingTailRecursion(num, 0));
return 0;
}
/*
Time: O(log n)
Space: O(log n)
*/
int sumOfDigits(int num) {
if(num == 0) {
return 0;
}
return (num % 10) + sumOfDigits(num / 10);
}
/*
Time: O(log n)
Space: O(1)
*/
int sumOfDigitsUsingTailRecursion(int num, int sum) {
if(num == 0) {
return sum;
}
return sumOfDigitsUsingTailRecursion(num / 10, sum + (num % 10));
}