<Codesignal> Rounders

Easy

We want to turn the given integer into a number that has only one non-zero digit using a tail rounding approach. This means that at each step we take the last non 0 digit of the number and round it to 0 or to 10. If it's less than 5 we round it to 0 if it's larger than or equal to 5 we round it to 10 (rounding to 10 means increasing the next significant digit by 1). The process stops immediately once there is only one non-zero digit left.

Example

• For n = 15, the output should be
  rounders(n) = 20;

• For n = 1234, the output should be
  rounders(n) = 1000.

  1234 -> 1230 -> 1200 -> 1000.

• For n = 1445, the output should be
  rounders(n) = 2000.

  1445 -> 1450 -> 1500 -> 2000.

Input/Output

• [execution time limit] 0.5 seconds (c)

• [input] integer n

  A positive integer.

  Guaranteed constraints:
  1 ≤ value ≤ 10^8.

• [output] integer

  • The rounded number.

[C] Syntax Tips

// Prints help message to the console
// Returns a string
char * helloWorld(char * name) {
    char * answer = malloc(strlen(name) + 8);
    printf("This prints to the console when you Run Tests");
    strcpy(answer, "Hello, ");
    strcat(answer, name);
    return answer;
}

---

Solution

int rounders(int n)
{
	int N=0;

	while(pow(10,N)<n)
	{
		if((n/(int)pow(10,N))%10>=5 && n/(int)pow(10,N+1)!=0)
			n+=(int)pow(10,N+1);
		n-=n%(int)pow(10,N);
		N++;
	}

	return n;
}