3. Digit Counts【medium】

Count the number of k's between 0 and n. k can be 0 - 9.

 

Example

if n = 12, k = 1 in

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]

we have FIVE 1's (1, 10, 11, 12)

解法一：

 class Solution {
  public:
     // param k : description of k
     // param n : description of n
     // return ans a integer
     int digitCounts(int k, int n) {
         int count = ;
         if (k == ) {
             count = ;
         }
         for (int i = ; i <= n; i++) {
             int number = i;
             while (number > ) {
                 if (number %  == k) {
                     count += ;
                 }
                 number /= ;
             }
         }

         return count;
     }
 };